Shotgun Shell and Shot Compositions

Abstract

Shot compositions and shotgun shells are described herein. Shot compositions comprising a plurality of shot pellets and a buffer are described, wherein the buffer comprises a plurality of pieces of plant material, such as walnut shell pieces. Shot compositions comprising a first plurality of shot pellets and a second plurality of shot pellets are also described, wherein the first plurality of shot pellets comprise tungsten and are smaller than the second plurality of shot pellets.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and benefit of U.S. provisional patent application No. 63 / 482,179, filed Jan. 30, 2023, the entire contents of which are incorporated by reference herein.TECHNICAL FIELD

[0002] This invention relates to shot compositions and shotgun shells comprising the same.BACKGROUND

[0003] A shotgun shell typically consists of a cartridge, a primer, gunpowder, shot and a wad or separating device between the powder which is then closed using a crimping die to close the shell.

[0004] Shotshell performance is commonly measured by the percentage of the plurality of shot pellets from within the individual shotshell that hit inside a 30 inch circle on a target. Common standards exist for pattern percentages at various distances, commonly 20, 30 and 40 yards. For instance, the most efficient patterns at long range (formed with a full choke at 40 yards) should yield at least 70% efficiency. There is a desire for shotshells with improved performance.

[0005] Shotshell environmental impact is of increasing interest. Federally mandated lead ammunition bans for migratory waterfowl date back to the late 1980s / early 1990s and more recent pressure at various state levels has eliminated or greatly limited the use of lead for other game. Accordingly, shot made from other non-lead materials has grown in popularity, including materials with density greater than steel shot, which can offer significant improvement in performance in terms of lethality and effective range. There is a need for shot that is more environmentally friendly, including non-lead shot.SUMMARY OF THE INVENTION

[0006] In efforts to continue to add technology to enhance the performance of all types of non-toxic ammunition, considerable effort has been invested into developing products that offer the hunter / shooter an improved product that improves kill percentages, reduces crippling and provides additional range in which lethal shots can be taken. In keeping with the spirit of environmental consciousness, efforts have been made to create such products that offers minimal, if any, negative impact on the environment. While the present technology has been developed for non-toxic, non-lead shot, the technology can also be implemented in shotshells that contain lead and can be used in areas where bans are not present.

[0007] The present invention provides shot compositions, shotgun shells comprising shot compositions, and associated methods of manufacture.

[0008] In one aspect, provided herein is a shot composition comprising a plurality of shot pellets and a buffer, wherein the buffer comprises a plurality of pieces of plant material.

[0009] In another aspect provided herein is a shot composition comprising: a first plurality of shot pellets comprising tungsten, and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a cross-sectional schematic of a shotshell according to an embodiment of the present invention with substantially uniformly mixed buffer.

[0011] FIG. 2 is a cross-sectional schematic of a shotshell according to another embodiment of the present invention with concentrated buffer proximal to the gunpowder.

[0012] FIG. 3 is a cross-sectional schematic of a shotshell according to another embodiments of the present invention with the buffer and shot pellets unmixed and separated by a spacer.

[0013] The figures are provided by way of example and are not intended to limit the scope of the invention.DETAILED DESCRIPTION

[0014] The present invention provides a shot composition comprising a plurality of shot pellets and a buffer, wherein the buffer comprises a plurality of pieces of plant material. The use of the buffer, being a plant material or organic material, advantageously provides improved utility for the shot composition, such as improved performance (e.g., pattern efficiency or depth of penetration) and / or reduced harm to the environment.

[0015] Buffers may be small particles, often many times smaller than the shot contained within the shell. Small buffer pieces may be mixed with the shot such that the buffer pieces settle in the interfacial openings that exist between the shot in the shotshell. Alternatively, buffers comprising pieces that are larger than the shot can also be employed. In some embodiments, the buffer is relatively evenly dispersed among the plurality of shot pellets. In other embodiments, the buffer is predominantly at the bottom of the shot column, closest to the gunpowder contained within the shotshell. A variety of methods may be employed to achieve a homogenous mix of buffer and shot. A preferred method is to dispense the buffer after the shot has been loaded into the cartridge and use a small pneumatic vibrator connected to a rail that makes contact with the shotshell. While it is possible to dispense the buffer into the cartridge prior to adding the shot, it becomes difficult for the shot pellets to settle into the buffer material. Other methods may be used such as premixing buffer and shot pellets or adding alternating portions of buffer and shot pellets to the cartridge with mixing or agitation.

[0016] The buffer comprises a plurality of pieces of plant material. In some embodiments, the plant material comprises nut shell or nut hull, preferably tree nut shell or tree nut hull, and most preferably walnut shell or walnut hull. In other embodiments, the plant material comprises corn cob. In some embodiments, the plant material is inert. In some embodiments, the plant material does not absorb moisture. In some embodiments, the plant material does not attract rodents. In some embodiments, the plant material does not have a propensity to mold in moist / humid storage environments.

[0017] The buffer pieces may be formed by breaking the plant material down into smaller pieces, such as by chopping, grinding, or other methods. In some embodiments, the buffer pieces are substantially uniform in size. In other embodiments, the buffer pieces vary in size. The buffer pieces may be substantially round in shape. Alternatively, the buffer pieces may have irregular shape or substantially planar shape or substantially cylindrical shape. The buffer pieces may have substantially uniform shape or varying shapes. In a preferred embodiment, the walnut shells are crushed walnut shells, also known as ground walnut shell, walnut shell grit, or walnut shell flour. Crushed walnut shells are commercially available in various fine and coarse sizes, as they are sometimes used in other applications such as sandblasting.

[0018] In some embodiments, the buffer pieces have an average diameter of from about 0.01 mm to about 4 mm. In some embodiments, the buffer pieces have an average diameter of from about 0.1 mm to about 1 mm. In some embodiments, the buffer pieces have an average volume per piece of from about 500 μm3 to about 30 mm3. In some embodiments, the buffer pieces have an average volume per piece of from about 0.0005 mm3 to about 0.5 mm3. In some embodiments, the buffer pieces have about a 40 / 100 mesh size. In some embodiments, the buffer pieces have an average mesh size of from about 16 mesh to about 400 mesh. In some embodiments, the buffer pieces are crushed walnut shell pieces of size 60 / 200 mesh to about size 6-10 mesh (e.g., size 60 / 200 mesh, 40 / 100 mesh, 35 / 60 mesh, 18-40 mesh, 14-30 mesh, 12-20 mesh, 8-12 mesh, or 6-10 mesh).

[0019] The shot pellets may be made from any suitable metals, such as those known for use in the art. In some embodiments, the plurality of shot pellets comprise lead, steel, bismuth, tin or zinc, or a combination thereof. In some embodiments, the shot pellets comprise lead. In some embodiments, the shot pellets are free of, or substantially free of, lead. In some embodiments, the shot pellets comprise bismuth. In some embodiments, the shot pellets are composed of at least 90 wt % bismuth. In some embodiments, the shot pellets are composed of at least 95 wt % or at least 99 wt % bismuth. In some embodiments, the shot pellets are composed of at least 90 wt % of a bismuth alloy. In some embodiments, the shot pellets are composed of at least 95 wt % or at least 99 wt % of a bismuth alloy. In some embodiments, the bismuth alloy comprises at least 50 wt % bismuth (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % tungsten). In some embodiments, the shot pellets are of substantially uniform composition.

[0020] The shot pellets may be plated or unplated. Plated shot pellets may be plated with copper. In some embodiments, the shot pellets may be plated bismuth shot pellets as described in US patent publication no. 2022 / 0316845 A1, the entire contents of which are incorporated herein by reference. For example, the shot pellets may be copper-plated bismuth.

[0021] The buffer pieces may be coated or uncoated. When coated, a preferred coating is graphite. Other coatings may also be employed such as boron nitride, wax, dry film lubricants such as molybdenum or powdered PTFE. Graphite coatings may be applied to walnut shell pieces by mixing the material in a common cement mixer, paint mixer, tumbler, or the like. Application of a surfactant prior to mixing can reduce dust. Light oil such as mineral oil may also be employed, e.g., in a ratio of 32 ounces of oil to 50 pounds of buffer.

[0022] In some embodiments, the shot pellets have an average diameter of from about 1 mm to about 10 mm. In some embodiments, the shot pellets have an average diameter of from about 2 mm to about 5 mm. In some embodiments, the shot pellets have a substantially uniform diameter of from about 1 mm to about 10 mm. In some embodiments, the shot pellets have a substantially uniform diameter of from about 2 mm to about 5 mm. In some embodiments, the shot pellets have a substantially uniform size of no greater than size BBB and no less than size #11. In some embodiments, the shot pellets have a substantially uniform size of no greater than size #1 and no less than size #9. In some embodiments, the shot pellets are size #4.

[0023] The buffer pieces may be smaller than, larger than, or of substantially equal size to the shot pellets, with smaller buffer pieces being preferred. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:2 to about 1:100. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:5 to about 1:50. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:10 to about 1:30.

[0024] The weight of buffer pieces and shot pellets, and in particular the weight ratio, in the composition may vary. In some embodiments, the ratio of the total weight of buffer to the total weight of the shot pellets is from about 1:5 to about 1:100. In some embodiments, the ratio of the total weight of buffer to the total weight of the shot pellets is from about 1:10 to about 1:50.

[0025] In some embodiments, the buffer is mixed among the plurality of shot pellets. In some embodiments, the buffer is substantially uniformly mixed among the plurality of shot pellets.

[0026] In some embodiments, the shot composition may further comprise a second plurality of shot pellets distinct from the first plurality of shot pellets in composition and / or size. The second plurality of shot pellets may comprise tungsten, and may be smaller than the first plurality of shot pellets, e.g., as described in other embodiments of this disclosure.

[0027] In another aspect, the present invention provides a shot composition comprising a first plurality of shot pellets comprising tungsten, and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets.

[0028] In this aspect, the tungsten pellets may be considered the “buffer.” Without being bound by theory, it is believed that the tungsten pellets provide shock dampening during setback not by cushioning the larger pellets (e.g., bismuth pellets), but by filling the air gaps between adjacent pellets thereby limiting the pellet deformation and improving pattern efficiencies. The tungsten pellets may be used in place of the plant-based buffers described herein, or may be used in combination with such plant-based buffers.

[0029] In some embodiments, the first plurality of shot pellets are composed of at least 90 wt % tungsten. In some embodiments, the first plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % tungsten. In some embodiments, the first plurality of shot pellets are composed or at least 90 wt % of a tungsten alloy. In some embodiments, the first plurality of shot pellets are composed or at least 95 wt % or at least 99 wt % of a tungsten alloy. In some embodiments, the tungsten alloy comprises at least 50 wt % tungsten (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % tungsten). Common tungsten alloys are tungsten / iron alloys and tungsten / nickel / iron alloys. In some embodiments, the first plurality of shot pellets are of substantially uniform composition.

[0030] In some embodiments, the second plurality of shot pellets comprise lead, steel, bismuth, tin or zinc. In some embodiments, the second plurality of shot pellets comprise lead. In some embodiments, the second plurality of shot pellets are free of, or substantially free of, lead. In some preferred embodiments, the second plurality of shot pellets comprise bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 90 wt % bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 90 wt % of a bismuth alloy. In some embodiments, the second plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % of a bismuth alloy. In some embodiments, the bismuth alloy comprises at least 50 wt % bismuth (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % bismuth). Common bismuth alloys include bismuth-tin alloys and bismuth-tin-tungsten alloys. In some embodiments, the second plurality of shot pellets are of substantially uniform composition.

[0031] The first plurality of shot pellets may be plated or unplated. Likewise, the second plurality of shot pellets may be plated or unplated. Where shot pellets or plated, the plating may be copper plating. In some embodiments, the second plurality of shot pellets may be plated bismuth shot pellets as described in US patent publication no. 2022 / 0316845 A1, the entire contents of which are incorporated herein by reference. For example, the shot pellets may be copper-plated bismuth.

[0032] In some embodiments, the first plurality of shot pellets have an average diameter of from about 1.5 mm to about 4 mm and the second plurality of shot pellets have an average diameter of from about 2 mm to about 10 mm. In some embodiments, the first plurality of shot pellets have a substantially uniform first pellet diameter of from about 1.5 mm to about 4 mm and the second plurality of shot pellets have a substantially uniform second pellet diameter of from about 2 mm to about 10 mm. In some embodiments, the second pellet diameter is from about 1.5 times larger to about 6 times larger than the first pellet diameter. Shot pellets are preferably spherical or substantially spherical in shape, consistent with suitable pellet shape known in the art. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #1 and no less than size #11. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #4 and no less than size #11. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #6 and no less than size #11. In some embodiments, the second plurality of shot pellets are of a substantially uniform size of no greater than size #BBB and no less than size #9. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #1 and no less than size #9. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #BBB and no less than size #6. In some embodiments, the first plurality of shot pellets are size #7, #8, #9, #10 or #11 and the second plurality of shot pellets are size #6, #5, #4, #3, #2, or #1. In some embodiments, the first plurality of shot pellets are size #9 and the second plurality of shot pellets are size #4.

[0033] In some embodiments, the weight ratio of the total weight of the first plurality of shot pellets to the total weight of the second plurality of shot pellets is from about 1:1 to about 1:10. In some embodiments, the weight ratio of the total weight of the first plurality of shot pellets to the total weight of the second plurality of shot pellets is from about 1:1.5 to about 1:5. In some embodiments, the first plurality of shot pellets are mixed among the second plurality of shot pellets. In some embodiments, the first plurality of shot pellets are substantially uniformly mixed among the second plurality of shot pellets.

[0034] The tungsten-containing shot compositions of this aspect may include a plant-based buffer or may be free of plant-based buffers. In some embodiments, the shot composition further comprises a buffer, wherein the buffer comprises a plurality of pieces of plant material. In some embodiments, the plant material is walnut shells or walnut hulls. In some embodiments, the buffer is mixed among the second plurality of shot pellets.

[0035] In another aspect, provided herein is a shotgun shell assembly comprising a cartridge loaded with a shot composition. In some embodiments, the shotgun shell assembly further comprises gunpowder. The shot composition may be any shot composition as described herein, including compositions with plant-based buffers, tungsten pellets, or both.

[0036] In some embodiments, the shotgun shell assembly comprises a plurality of shot pellets and a plant-based buffer. In some such embodiments, the pellets and buffer are substantially uniformly mixed among each other within a shot-containing portion of the cartridge. In some embodiments, the concentration of buffer pieces within the shot composition is greater near or proximal to the gunpowder or wad and lesser elsewhere within the shot composition, including distal to the gunpowder or wad.

[0037] In other embodiments, the shot composition within the cartridge may comprise a first plurality of shot pellets comprising tungsten and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets. In some embodiments, the first plurality of shot pellets are substantially uniformly mixed among the second plurality of shot pellets

[0038] In some embodiments, gunpowder is disposed within the cartridge near a first end of the cartridge the shot composition is disposed within the cartridge near a second, opposite end of the cartridge. In some embodiments, smaller pieces, either plant-based buffer or tungsten-based shot pellets (or both) are mixed among the larger shot pellets. In some embodiments, the concentration of the smaller pieces (either plant-based buffer or tungsten-based shot pellets, or both) have a greater concentration proximal to the gunpowder and lesser concentration distal to the gunpowder.

[0039] Referring to FIG. 1, a schematic embodiment of a shotgun shell assembly 10 is shown. The assembly 10 includes a cartridge 12 that houses the components of the assembly. Inside the cartridge 12 are the shot pellets 14 and buffer pieces 16 that make up the shot composition. The buffer pieces 16 may be pieces of plant material, as described herein. Alternatively, the buffer pieces may be (or may be replaced with) shot pellets comprising tungsten, as described herein. In FIG. 1, the buffer pieces 16 are substantially uniformly mixed among the shot pellets 14. The assembly 10 further includes gunpowder 18, which is separated from the shot composition 14, 16 by a wad 20. The gunpowder is loaded near a first end 22 and the shot pellets 14 and buffer pieces 16 are loaded near a second end 24. The first end 22 can be considered the bottom of the assembly 10 and the second end 24 can be considered the top of the assembly 10. As such, the gunpowder 18 can be described as below the shot composition 14, 16 and likewise the shot composition can be described as above the gunpowder.

[0040] Referring to FIG. 2, another schematic embodiment of a shotgun shell assembly 10 is shown with the same components, but with the shot pellets 14 and buffer pieces 16 in a different arrangement. In the embodiment of FIG. 2, the shot composition includes a zone a with concentrated buffer (and fewer shot pellets), and a zone b that does not have concentrated buffer, i.e., has a lower concentration of buffer pieces compared to zone a.

[0041] Referring to FIG. 3, another schematic embodiment of a shotgun shell assembly 10 is shown with the same components plus the addition of a spacer 26 and with the shot pellets 14 and buffer pieces 16 in an alternate arrangement. In the embodiment of FIG. 3, the buffer pieces 16 are not mixed with the shot pellets 14. The spacer 26 separates the buffer pieces 16 from the shot pellets 14. In alternate embodiments (not shown), the spacer 26 is absent and the buffer pieces 16 and shot pellets 14 are directly adjacent, but still not mixed. In FIG. 3, the buffer pieces are proximal to the gunpowder 18 and wad 20, and the shot pellets are distal to the gunpowder 18 and wad 20 (and proximal to the second end 24. Or stated differently, the shot pellets 14 are loaded above the buffer pieces 16. In alternate embodiments (not shown), the buffer pieces 16 are loaded above the shot pellets 14.

[0042] In some embodiments of a shotgun shell assembly, the assembly comprises a spacer separating the buffer pieces and shot pellets (or separating the first plurality of shot pellets and the second plurality of shot pellets). In some embodiments, the spacer is a felt cushion or a cork cushion. The shot pellets may be loaded above the buffer pieces, or alternatively, the buffer pieces may be loaded above the shot pellets.

[0043] In some embodiments, the shotgun shell assembly comprises additional suitable shotgun shell components, such as primer, gunpowder, wad, slug, shell case, and the like.

[0044] Fine particles sizes of buffer can be used to increase chamber pressure as desired. Due care should be taken with regard to chamber pressures. Use of buffer pieces (particularly smaller buffer pieces) may also allow reduced gunpowder charges due to increased efficiency. In instances where reduced powder charges still create high chamber pressure, slower gunpowder (reduced burn rate) can be used. Different shell closure techniques may also be employed such as shallower crimp height of the shell, finish taper adjustment, few petals in the crimp closure, or even conventional roll crimp with an overshot card made of paper, plastic, fiber, or a disc of similar design. The various aspects of the invention can be employed to various common shotgun calibers such as 10 ga, 16 ga, 20 ga, 28, ga, 32 ga, 36 ga, and 0.410 bore.EXAMPLESExample 1—Bismuth Shot with Walnut Shell Buffer

[0045] A shotshell comprising bismuth shot and walnut shell buffer was prepared. The components of the shotshell were as follows:

[0046] Cheddite 12 ga 2¾″ Hull

[0047] 25.5 grains St. Marks OBP 473 powder

[0048] Gualandi 42 mm Cushioned Wad

[0049] 1¼ oz Copper Plated Bismuth Shot, #4 size

[0050] 22 grains of walnut shell buffer (about 0.05 ounces), 40 / 100 mesh, graphite coated

[0051] 6 petal crimp, Roll Finished with #2 12 ga die

[0052] Crimp Depth of 0.050″

[0053] A non-buffered shotshell was also prepared as a control using the same components and assembly method but without the buffer.

[0054] A test was conducted using a single block of ballistic gelatin and fired at a measured distance of 30 yards. A steel plate covered one half of the gel block and the non-buffered shell was fired. The steel plate was then placed over the previously fired half and shot at the same distance within 1 minute of the first shot. The distance of penetration of the pellets that struck the gelatin was measured. The data is shown in Table 1 below. The data show that the buffered shot composition had a 7.7% greater average depth of penetration compared to the non-buffered shot composition. Without being bound by theory, it is believed that the increase in depth of penetration results from increased efficiency and retained energy due to a decrease in pellet deformation (during setback and rapid acceleration of the shot column while traveling down the barrel of the shotgun firing the shotshell) for the buffered shot composition.TABLE 1Penetration in Ballistic Gelatin BlockNon Buffered #4Buffered #444.253.8754.3753.62554.754.254.54.54.54.53.93754.34.254.875Average4.180 inches4.506 inchesSTD Dev0.38300605530.2855914915Variance0.14669363840.0815625

[0055] The buffered and non-buffered shot were further tested for pattern efficiency when fired at targets at distances of 30, 40 and 50 yards. Pattern efficiency was defined as the percentage of the plurality of pellets from the shotshell that struck the target inside a 30″ circle.

[0056] The performance data for the buffered shot was as follows:

[0057] 1380 FPS Muzzle Velocity

[0058] 12,000 PSI

[0059] 30 yard Pattern Efficiency: 98.3%

[0060] 40 yard Pattern Efficiency: 81.1%

[0061] 50 yard Pattern Efficiency: 62.9%

[0062] The non-buffered shot had the following performance data:

[0063] 1376 FPS Muzzle Velocity

[0064] 9,700 PSI

[0065] 30 yard Pattern Efficiency: 96%

[0066] 40 yard Pattern Efficiency: 68%

[0067] 50 yard Pattern Efficiency: 48.6%

[0068] The data show that the buffered shot had improved performance in pattern efficiency, particularly at long range.Example 2—Bismuth Shot with Tungsten Buffer

[0069] Shot compositions were prepared with bismuth shot and a tungsten buffer. To test the performance improvement of the tungsten / bismuth blend, variations of the same components were tested as follows:

[0070] Shotshell components:

[0071] Cheddite 12 ga 2¾″ Hull

[0072] 25.5 grains St. Marks OBP 473 powder

[0073] Gualandi 42 mm Cushioned Wad

[0074] 1-oz Copper Plated Bismuth Shot, #4 size

[0075] ½ oz Tungsten Shot (TSS), #9 size

[0076] 6 petal crimp, Roll Finished with #2 12 ga die

[0077] Crimp Depth of 0.050″

[0078] Trial 1: The tungsten was loaded first, at the bottom of the shot column, followed by the Bismuth being directly placed on top of the tungsten shot.

[0079] Trial 2: The bismuth shot was loaded first, at the bottom of the shot column, followed by the Tungsten being directly placed on top of the bismuth shot.

[0080] Trial 3: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the bismuth loaded at the top of the shot column.

[0081] Trial 4: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick cork cushion, followed by the bismuth loaded at the top of the shot column.

[0082] Trial 5: The bismuth shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the tungsten loaded at the top of the shot column.

[0083] Trial 6: The bismuth shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick cork cushion, followed by the tungsten loaded at the top of the shot column.

[0084] Trial 7: The bismuth shot was loaded first, at the bottom of the shot column followed by the tungsten placed directly on top of the bismuth. The shell was subjected to vibration in a similar manner to the aforementioned design using the organic buffer.

[0085] Performance of the shotshells was tested for pattern efficiency by firing on a target at 50 yards, with the data presented below in Table 2. Pattern efficiency was calculated in the same manner as Example 1.TABLE 2Pattern Efficiency with Tungsten Buffer at 50 YardsBiTungstenPrototype 359 Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS Bottom49.439.954.64Cork SpacerBismuth TopTrialTSS Top50.645.953.16Cork SpacerBismuthBottomTrialTSS Bottom46.143.947.33Felt SpacerBismuth TopTrialTSS Top Felt55.150.757.55SpacerBismuthBottomTrialTSS Bottom4740.550.51Bismuth TopTrialTSS Top48.245.349.82BismuthBottomTrialTSS +4836.554.27BismuthMixed

[0086] The data suggests that the improvements in the pattern yield benefit not only to the increased pattern efficiency of the bismuth and tungsten pellets without an organic buffer when compared to an all bismuth shell loaded with the same wad. By selecting a wad with a cushion section that allows for minimal height adjustment upon closure, the shell can be assembled in such a fashion that prevents migration of pellets to the top or bottom of the shot column as the closure forces effectively lock the pellets within the column in place. The benefit in using such a technology allows for the shooter to achieve increased range at longer distances due to the significant increase in density of tungsten (which measures anywhere from 12-19 g / cc) when compared to Bismuth (typically 9-10 g / cc).Example 3—Shot Composition with Bismuth Shot and Walnut and Tungsten Buffer

[0087] Shotshells similar to Example 2 were prepared but with a combination of the two buffer technologies, plant-based buffer and the high density tungsten buffer. The combined buffer resulted in slightly higher pattern efficiencies as compared to the pattern efficiencies of the tungsten only buffer. The results are presented in Table 3.TABLE 3Pattern Efficiency with Walnut and Tungsten Buffer at 50 YardsBiTungstenPrototype 359 w / Organic Buffer Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS + Buffer50.941.156.24Bottom CorkSpacer BismuthTopTrialTSS + Buffer51.947.054.46Top CorkSpacer BismuthBottomTrialTSS + Buffer47.144.948.43Bottom FeltSpacer BismuthTopTrialTSS + Buffer56.351.858.85Top Felt SpacerBismuthBottomTrialTSS + Buffer48.441.752.01BottomBismuth TopTrialTSS + Buffer49.546.551.12Top BismuthBottomTrialTSS + Buffer +49.437.655.87Bismuth MixedOther Embodiments

[0088] It should be apparent that the foregoing relates only to the preferred embodiments of the present invention and that numerous changes and modifications may be made herein without departing from the spirit and scope of the invention as defined by the following claims and equivalents thereof.

Examples

example 1

Bismuth Shot with Walnut Shell Buffer

[0045]A shotshell comprising bismuth shot and walnut shell buffer was prepared. The components of the shotshell were as follows:[0046]Cheddite 12 ga 2¾″ Hull[0047]25.5 grains St. Marks OBP 473 powder[0048]Gualandi 42 mm Cushioned Wad[0049]1¼ oz Copper Plated Bismuth Shot, #4 size[0050]22 grains of walnut shell buffer (about 0.05 ounces), 40 / 100 mesh, graphite coated[0051]6 petal crimp, Roll Finished with #2 12 ga die[0052]Crimp Depth of 0.050″

[0053]A non-buffered shotshell was also prepared as a control using the same components and assembly method but without the buffer.

[0054]A test was conducted using a single block of ballistic gelatin and fired at a measured distance of 30 yards. A steel plate covered one half of the gel block and the non-buffered shell was fired. The steel plate was then placed over the previously fired half and shot at the same distance within 1 minute of the first shot. The distance of penetration of the pellets that struc...

example 2

Bismuth Shot with Tungsten Buffer

[0069]Shot compositions were prepared with bismuth shot and a tungsten buffer. To test the performance improvement of the tungsten / bismuth blend, variations of the same components were tested as follows:

[0070]Shotshell components:[0071]Cheddite 12 ga 2¾″ Hull[0072]25.5 grains St. Marks OBP 473 powder[0073]Gualandi 42 mm Cushioned Wad[0074]1-oz Copper Plated Bismuth Shot, #4 size[0075]½ oz Tungsten Shot (TSS), #9 size[0076]6 petal crimp, Roll Finished with #2 12 ga die[0077]Crimp Depth of 0.050″[0078]Trial 1: The tungsten was loaded first, at the bottom of the shot column, followed by the Bismuth being directly placed on top of the tungsten shot.[0079]Trial 2: The bismuth shot was loaded first, at the bottom of the shot column, followed by the Tungsten being directly placed on top of the bismuth shot.[0080]Trial 3: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the bismuth loaded ...

example 3

Shot Composition with Bismuth Shot and Walnut and Tungsten Buffer

[0087]Shotshells similar to Example 2 were prepared but with a combination of the two buffer technologies, plant-based buffer and the high density tungsten buffer. The combined buffer resulted in slightly higher pattern efficiencies as compared to the pattern efficiencies of the tungsten only buffer. The results are presented in Table 3.

TABLE 3Pattern Efficiency with Walnut and Tungsten Buffer at 50 YardsBiTungstenPrototype 359 w / Organic Buffer Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS + Buffer50.941.156.24Bottom CorkSpacer BismuthTopTrialTSS + Buffer51.947.054.46Top CorkSpacer BismuthBottomTrialTSS + Buffer47.144.948.43Bottom FeltSpacer BismuthTopTrialTSS + Buffer56.351.858.85Top Felt SpacerBismuthBottomTrialTSS + Buffer48.441.752.01BottomBismuth TopTrialTSS + Buffer49.546.551.12Top BismuthBottomTrialTSS + Buffer +49.437.655.87...

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and benefit of U.S. provisional patent application No. 63 / 482,179, filed Jan. 30, 2023, the entire contents of which are incorporated by reference herein.TECHNICAL FIELD

[0002] This invention relates to shot compositions and shotgun shells comprising the same.BACKGROUND

[0003] A shotgun shell typically consists of a cartridge, a primer, gunpowder, shot and a wad or separating device between the powder which is then closed using a crimping die to close the shell.

[0004] Shotshell performance is commonly measured by the percentage of the plurality of shot pellets from within the individual shotshell that hit inside a 30 inch circle on a target. Common standards exist for pattern percentages at various distances, commonly 20, 30 and 40 yards. For instance, the most efficient patterns at long range (formed with a full choke at 40 yards) should yield at least 70% efficiency. There is a desire for shotshells with improved performance.

[0005] Shotshell environmental impact is of increasing interest. Federally mandated lead ammunition bans for migratory waterfowl date back to the late 1980s / early 1990s and more recent pressure at various state levels has eliminated or greatly limited the use of lead for other game. Accordingly, shot made from other non-lead materials has grown in popularity, including materials with density greater than steel shot, which can offer significant improvement in performance in terms of lethality and effective range. There is a need for shot that is more environmentally friendly, including non-lead shot.SUMMARY OF THE INVENTION

[0006] In efforts to continue to add technology to enhance the performance of all types of non-toxic ammunition, considerable effort has been invested into developing products that offer the hunter / shooter an improved product that improves kill percentages, reduces crippling and provides additional range in which lethal shots can be taken. In keeping with the spirit of environmental consciousness, efforts have been made to create such products that offers minimal, if any, negative impact on the environment. While the present technology has been developed for non-toxic, non-lead shot, the technology can also be implemented in shotshells that contain lead and can be used in areas where bans are not present.

[0007] The present invention provides shot compositions, shotgun shells comprising shot compositions, and associated methods of manufacture.

[0008] In one aspect, provided herein is a shot composition comprising a plurality of shot pellets and a buffer, wherein the buffer comprises a plurality of pieces of plant material.

[0009] In another aspect provided herein is a shot composition comprising: a first plurality of shot pellets comprising tungsten, and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a cross-sectional schematic of a shotshell according to an embodiment of the present invention with substantially uniformly mixed buffer.

[0011] FIG. 2 is a cross-sectional schematic of a shotshell according to another embodiment of the present invention with concentrated buffer proximal to the gunpowder.

[0012] FIG. 3 is a cross-sectional schematic of a shotshell according to another embodiments of the present invention with the buffer and shot pellets unmixed and separated by a spacer.

[0013] The figures are provided by way of example and are not intended to limit the scope of the invention.DETAILED DESCRIPTION

[0014] The present invention provides a shot composition comprising a plurality of shot pellets and a buffer, wherein the buffer comprises a plurality of pieces of plant material. The use of the buffer, being a plant material or organic material, advantageously provides improved utility for the shot composition, such as improved performance (e.g., pattern efficiency or depth of penetration) and / or reduced harm to the environment.

[0015] Buffers may be small particles, often many times smaller than the shot contained within the shell. Small buffer pieces may be mixed with the shot such that the buffer pieces settle in the interfacial openings that exist between the shot in the shotshell. Alternatively, buffers comprising pieces that are larger than the shot can also be employed. In some embodiments, the buffer is relatively evenly dispersed among the plurality of shot pellets. In other embodiments, the buffer is predominantly at the bottom of the shot column, closest to the gunpowder contained within the shotshell. A variety of methods may be employed to achieve a homogenous mix of buffer and shot. A preferred method is to dispense the buffer after the shot has been loaded into the cartridge and use a small pneumatic vibrator connected to a rail that makes contact with the shotshell. While it is possible to dispense the buffer into the cartridge prior to adding the shot, it becomes difficult for the shot pellets to settle into the buffer material. Other methods may be used such as premixing buffer and shot pellets or adding alternating portions of buffer and shot pellets to the cartridge with mixing or agitation.

[0016] The buffer comprises a plurality of pieces of plant material. In some embodiments, the plant material comprises nut shell or nut hull, preferably tree nut shell or tree nut hull, and most preferably walnut shell or walnut hull. In other embodiments, the plant material comprises corn cob. In some embodiments, the plant material is inert. In some embodiments, the plant material does not absorb moisture. In some embodiments, the plant material does not attract rodents. In some embodiments, the plant material does not have a propensity to mold in moist / humid storage environments.

[0017] The buffer pieces may be formed by breaking the plant material down into smaller pieces, such as by chopping, grinding, or other methods. In some embodiments, the buffer pieces are substantially uniform in size. In other embodiments, the buffer pieces vary in size. The buffer pieces may be substantially round in shape. Alternatively, the buffer pieces may have irregular shape or substantially planar shape or substantially cylindrical shape. The buffer pieces may have substantially uniform shape or varying shapes. In a preferred embodiment, the walnut shells are crushed walnut shells, also known as ground walnut shell, walnut shell grit, or walnut shell flour. Crushed walnut shells are commercially available in various fine and coarse sizes, as they are sometimes used in other applications such as sandblasting.

[0018] In some embodiments, the buffer pieces have an average diameter of from about 0.01 mm to about 4 mm. In some embodiments, the buffer pieces have an average diameter of from about 0.1 mm to about 1 mm. In some embodiments, the buffer pieces have an average volume per piece of from about 500 μm3 to about 30 mm3. In some embodiments, the buffer pieces have an average volume per piece of from about 0.0005 mm3 to about 0.5 mm3. In some embodiments, the buffer pieces have about a 40 / 100 mesh size. In some embodiments, the buffer pieces have an average mesh size of from about 16 mesh to about 400 mesh. In some embodiments, the buffer pieces are crushed walnut shell pieces of size 60 / 200 mesh to about size 6-10 mesh (e.g., size 60 / 200 mesh, 40 / 100 mesh, 35 / 60 mesh, 18-40 mesh, 14-30 mesh, 12-20 mesh, 8-12 mesh, or 6-10 mesh).

[0019] The shot pellets may be made from any suitable metals, such as those known for use in the art. In some embodiments, the plurality of shot pellets comprise lead, steel, bismuth, tin or zinc, or a combination thereof. In some embodiments, the shot pellets comprise lead. In some embodiments, the shot pellets are free of, or substantially free of, lead. In some embodiments, the shot pellets comprise bismuth. In some embodiments, the shot pellets are composed of at least 90 wt % bismuth. In some embodiments, the shot pellets are composed of at least 95 wt % or at least 99 wt % bismuth. In some embodiments, the shot pellets are composed of at least 90 wt % of a bismuth alloy. In some embodiments, the shot pellets are composed of at least 95 wt % or at least 99 wt % of a bismuth alloy. In some embodiments, the bismuth alloy comprises at least 50 wt % bismuth (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % tungsten). In some embodiments, the shot pellets are of substantially uniform composition.

[0020] The shot pellets may be plated or unplated. Plated shot pellets may be plated with copper. In some embodiments, the shot pellets may be plated bismuth shot pellets as described in US patent publication no. 2022 / 0316845 A1, the entire contents of which are incorporated herein by reference. For example, the shot pellets may be copper-plated bismuth.

[0021] The buffer pieces may be coated or uncoated. When coated, a preferred coating is graphite. Other coatings may also be employed such as boron nitride, wax, dry film lubricants such as molybdenum or powdered PTFE. Graphite coatings may be applied to walnut shell pieces by mixing the material in a common cement mixer, paint mixer, tumbler, or the like. Application of a surfactant prior to mixing can reduce dust. Light oil such as mineral oil may also be employed, e.g., in a ratio of 32 ounces of oil to 50 pounds of buffer.

[0022] In some embodiments, the shot pellets have an average diameter of from about 1 mm to about 10 mm. In some embodiments, the shot pellets have an average diameter of from about 2 mm to about 5 mm. In some embodiments, the shot pellets have a substantially uniform diameter of from about 1 mm to about 10 mm. In some embodiments, the shot pellets have a substantially uniform diameter of from about 2 mm to about 5 mm. In some embodiments, the shot pellets have a substantially uniform size of no greater than size BBB and no less than size #11. In some embodiments, the shot pellets have a substantially uniform size of no greater than size #1 and no less than size #9. In some embodiments, the shot pellets are size #4.

[0023] The buffer pieces may be smaller than, larger than, or of substantially equal size to the shot pellets, with smaller buffer pieces being preferred. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:2 to about 1:100. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:5 to about 1:50. In some embodiments, the ratio of the average diameter of the buffer pieces to the average diameter of the shot pellets is from about 1:10 to about 1:30.

[0024] The weight of buffer pieces and shot pellets, and in particular the weight ratio, in the composition may vary. In some embodiments, the ratio of the total weight of buffer to the total weight of the shot pellets is from about 1:5 to about 1:100. In some embodiments, the ratio of the total weight of buffer to the total weight of the shot pellets is from about 1:10 to about 1:50.

[0025] In some embodiments, the buffer is mixed among the plurality of shot pellets. In some embodiments, the buffer is substantially uniformly mixed among the plurality of shot pellets.

[0026] In some embodiments, the shot composition may further comprise a second plurality of shot pellets distinct from the first plurality of shot pellets in composition and / or size. The second plurality of shot pellets may comprise tungsten, and may be smaller than the first plurality of shot pellets, e.g., as described in other embodiments of this disclosure.

[0027] In another aspect, the present invention provides a shot composition comprising a first plurality of shot pellets comprising tungsten, and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets.

[0028] In this aspect, the tungsten pellets may be considered the “buffer.” Without being bound by theory, it is believed that the tungsten pellets provide shock dampening during setback not by cushioning the larger pellets (e.g., bismuth pellets), but by filling the air gaps between adjacent pellets thereby limiting the pellet deformation and improving pattern efficiencies. The tungsten pellets may be used in place of the plant-based buffers described herein, or may be used in combination with such plant-based buffers.

[0029] In some embodiments, the first plurality of shot pellets are composed of at least 90 wt % tungsten. In some embodiments, the first plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % tungsten. In some embodiments, the first plurality of shot pellets are composed or at least 90 wt % of a tungsten alloy. In some embodiments, the first plurality of shot pellets are composed or at least 95 wt % or at least 99 wt % of a tungsten alloy. In some embodiments, the tungsten alloy comprises at least 50 wt % tungsten (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % tungsten). Common tungsten alloys are tungsten / iron alloys and tungsten / nickel / iron alloys. In some embodiments, the first plurality of shot pellets are of substantially uniform composition.

[0030] In some embodiments, the second plurality of shot pellets comprise lead, steel, bismuth, tin or zinc. In some embodiments, the second plurality of shot pellets comprise lead. In some embodiments, the second plurality of shot pellets are free of, or substantially free of, lead. In some preferred embodiments, the second plurality of shot pellets comprise bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 90 wt % bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % bismuth. In some embodiments, the second plurality of shot pellets are composed of at least 90 wt % of a bismuth alloy. In some embodiments, the second plurality of shot pellets are composed of at least 95 wt % or at least 99 wt % of a bismuth alloy. In some embodiments, the bismuth alloy comprises at least 50 wt % bismuth (e.g., at least 60 wt %, at least 70 wt %, at least 80 wt % or at least 90 wt % bismuth). Common bismuth alloys include bismuth-tin alloys and bismuth-tin-tungsten alloys. In some embodiments, the second plurality of shot pellets are of substantially uniform composition.

[0031] The first plurality of shot pellets may be plated or unplated. Likewise, the second plurality of shot pellets may be plated or unplated. Where shot pellets or plated, the plating may be copper plating. In some embodiments, the second plurality of shot pellets may be plated bismuth shot pellets as described in US patent publication no. 2022 / 0316845 A1, the entire contents of which are incorporated herein by reference. For example, the shot pellets may be copper-plated bismuth.

[0032] In some embodiments, the first plurality of shot pellets have an average diameter of from about 1.5 mm to about 4 mm and the second plurality of shot pellets have an average diameter of from about 2 mm to about 10 mm. In some embodiments, the first plurality of shot pellets have a substantially uniform first pellet diameter of from about 1.5 mm to about 4 mm and the second plurality of shot pellets have a substantially uniform second pellet diameter of from about 2 mm to about 10 mm. In some embodiments, the second pellet diameter is from about 1.5 times larger to about 6 times larger than the first pellet diameter. Shot pellets are preferably spherical or substantially spherical in shape, consistent with suitable pellet shape known in the art. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #1 and no less than size #11. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #4 and no less than size #11. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #6 and no less than size #11. In some embodiments, the second plurality of shot pellets are of a substantially uniform size of no greater than size #BBB and no less than size #9. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #1 and no less than size #9. In some embodiments, the first plurality of shot pellets are of a substantially uniform size of no greater than size #BBB and no less than size #6. In some embodiments, the first plurality of shot pellets are size #7, #8, #9, #10 or #11 and the second plurality of shot pellets are size #6, #5, #4, #3, #2, or #1. In some embodiments, the first plurality of shot pellets are size #9 and the second plurality of shot pellets are size #4.

[0033] In some embodiments, the weight ratio of the total weight of the first plurality of shot pellets to the total weight of the second plurality of shot pellets is from about 1:1 to about 1:10. In some embodiments, the weight ratio of the total weight of the first plurality of shot pellets to the total weight of the second plurality of shot pellets is from about 1:1.5 to about 1:5. In some embodiments, the first plurality of shot pellets are mixed among the second plurality of shot pellets. In some embodiments, the first plurality of shot pellets are substantially uniformly mixed among the second plurality of shot pellets.

[0034] The tungsten-containing shot compositions of this aspect may include a plant-based buffer or may be free of plant-based buffers. In some embodiments, the shot composition further comprises a buffer, wherein the buffer comprises a plurality of pieces of plant material. In some embodiments, the plant material is walnut shells or walnut hulls. In some embodiments, the buffer is mixed among the second plurality of shot pellets.

[0035] In another aspect, provided herein is a shotgun shell assembly comprising a cartridge loaded with a shot composition. In some embodiments, the shotgun shell assembly further comprises gunpowder. The shot composition may be any shot composition as described herein, including compositions with plant-based buffers, tungsten pellets, or both.

[0036] In some embodiments, the shotgun shell assembly comprises a plurality of shot pellets and a plant-based buffer. In some such embodiments, the pellets and buffer are substantially uniformly mixed among each other within a shot-containing portion of the cartridge. In some embodiments, the concentration of buffer pieces within the shot composition is greater near or proximal to the gunpowder or wad and lesser elsewhere within the shot composition, including distal to the gunpowder or wad.

[0037] In other embodiments, the shot composition within the cartridge may comprise a first plurality of shot pellets comprising tungsten and a second plurality of shot pellets, wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, and wherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets. In some embodiments, the first plurality of shot pellets are substantially uniformly mixed among the second plurality of shot pellets

[0038] In some embodiments, gunpowder is disposed within the cartridge near a first end of the cartridge the shot composition is disposed within the cartridge near a second, opposite end of the cartridge. In some embodiments, smaller pieces, either plant-based buffer or tungsten-based shot pellets (or both) are mixed among the larger shot pellets. In some embodiments, the concentration of the smaller pieces (either plant-based buffer or tungsten-based shot pellets, or both) have a greater concentration proximal to the gunpowder and lesser concentration distal to the gunpowder.

[0039] Referring to FIG. 1, a schematic embodiment of a shotgun shell assembly 10 is shown. The assembly 10 includes a cartridge 12 that houses the components of the assembly. Inside the cartridge 12 are the shot pellets 14 and buffer pieces 16 that make up the shot composition. The buffer pieces 16 may be pieces of plant material, as described herein. Alternatively, the buffer pieces may be (or may be replaced with) shot pellets comprising tungsten, as described herein. In FIG. 1, the buffer pieces 16 are substantially uniformly mixed among the shot pellets 14. The assembly 10 further includes gunpowder 18, which is separated from the shot composition 14, 16 by a wad 20. The gunpowder is loaded near a first end 22 and the shot pellets 14 and buffer pieces 16 are loaded near a second end 24. The first end 22 can be considered the bottom of the assembly 10 and the second end 24 can be considered the top of the assembly 10. As such, the gunpowder 18 can be described as below the shot composition 14, 16 and likewise the shot composition can be described as above the gunpowder.

[0040] Referring to FIG. 2, another schematic embodiment of a shotgun shell assembly 10 is shown with the same components, but with the shot pellets 14 and buffer pieces 16 in a different arrangement. In the embodiment of FIG. 2, the shot composition includes a zone a with concentrated buffer (and fewer shot pellets), and a zone b that does not have concentrated buffer, i.e., has a lower concentration of buffer pieces compared to zone a.

[0041] Referring to FIG. 3, another schematic embodiment of a shotgun shell assembly 10 is shown with the same components plus the addition of a spacer 26 and with the shot pellets 14 and buffer pieces 16 in an alternate arrangement. In the embodiment of FIG. 3, the buffer pieces 16 are not mixed with the shot pellets 14. The spacer 26 separates the buffer pieces 16 from the shot pellets 14. In alternate embodiments (not shown), the spacer 26 is absent and the buffer pieces 16 and shot pellets 14 are directly adjacent, but still not mixed. In FIG. 3, the buffer pieces are proximal to the gunpowder 18 and wad 20, and the shot pellets are distal to the gunpowder 18 and wad 20 (and proximal to the second end 24. Or stated differently, the shot pellets 14 are loaded above the buffer pieces 16. In alternate embodiments (not shown), the buffer pieces 16 are loaded above the shot pellets 14.

[0042] In some embodiments of a shotgun shell assembly, the assembly comprises a spacer separating the buffer pieces and shot pellets (or separating the first plurality of shot pellets and the second plurality of shot pellets). In some embodiments, the spacer is a felt cushion or a cork cushion. The shot pellets may be loaded above the buffer pieces, or alternatively, the buffer pieces may be loaded above the shot pellets.

[0043] In some embodiments, the shotgun shell assembly comprises additional suitable shotgun shell components, such as primer, gunpowder, wad, slug, shell case, and the like.

[0044] Fine particles sizes of buffer can be used to increase chamber pressure as desired. Due care should be taken with regard to chamber pressures. Use of buffer pieces (particularly smaller buffer pieces) may also allow reduced gunpowder charges due to increased efficiency. In instances where reduced powder charges still create high chamber pressure, slower gunpowder (reduced burn rate) can be used. Different shell closure techniques may also be employed such as shallower crimp height of the shell, finish taper adjustment, few petals in the crimp closure, or even conventional roll crimp with an overshot card made of paper, plastic, fiber, or a disc of similar design. The various aspects of the invention can be employed to various common shotgun calibers such as 10 ga, 16 ga, 20 ga, 28, ga, 32 ga, 36 ga, and 0.410 bore.EXAMPLESExample 1—Bismuth Shot with Walnut Shell Buffer

[0045] A shotshell comprising bismuth shot and walnut shell buffer was prepared. The components of the shotshell were as follows:

[0046] Cheddite 12 ga 2¾″ Hull

[0047] 25.5 grains St. Marks OBP 473 powder

[0048] Gualandi 42 mm Cushioned Wad

[0049] 1¼ oz Copper Plated Bismuth Shot, #4 size

[0050] 22 grains of walnut shell buffer (about 0.05 ounces), 40 / 100 mesh, graphite coated

[0051] 6 petal crimp, Roll Finished with #2 12 ga die

[0052] Crimp Depth of 0.050″

[0053] A non-buffered shotshell was also prepared as a control using the same components and assembly method but without the buffer.

[0054] A test was conducted using a single block of ballistic gelatin and fired at a measured distance of 30 yards. A steel plate covered one half of the gel block and the non-buffered shell was fired. The steel plate was then placed over the previously fired half and shot at the same distance within 1 minute of the first shot. The distance of penetration of the pellets that struck the gelatin was measured. The data is shown in Table 1 below. The data show that the buffered shot composition had a 7.7% greater average depth of penetration compared to the non-buffered shot composition. Without being bound by theory, it is believed that the increase in depth of penetration results from increased efficiency and retained energy due to a decrease in pellet deformation (during setback and rapid acceleration of the shot column while traveling down the barrel of the shotgun firing the shotshell) for the buffered shot composition.TABLE 1Penetration in Ballistic Gelatin BlockNon Buffered #4Buffered #444.253.8754.3753.62554.754.254.54.54.54.53.93754.34.254.875Average4.180 inches4.506 inchesSTD Dev0.38300605530.2855914915Variance0.14669363840.0815625

[0055] The buffered and non-buffered shot were further tested for pattern efficiency when fired at targets at distances of 30, 40 and 50 yards. Pattern efficiency was defined as the percentage of the plurality of pellets from the shotshell that struck the target inside a 30″ circle.

[0056] The performance data for the buffered shot was as follows:

[0057] 1380 FPS Muzzle Velocity

[0058] 12,000 PSI

[0059] 30 yard Pattern Efficiency: 98.3%

[0060] 40 yard Pattern Efficiency: 81.1%

[0061] 50 yard Pattern Efficiency: 62.9%

[0062] The non-buffered shot had the following performance data:

[0063] 1376 FPS Muzzle Velocity

[0064] 9,700 PSI

[0065] 30 yard Pattern Efficiency: 96%

[0066] 40 yard Pattern Efficiency: 68%

[0067] 50 yard Pattern Efficiency: 48.6%

[0068] The data show that the buffered shot had improved performance in pattern efficiency, particularly at long range.Example 2—Bismuth Shot with Tungsten Buffer

[0069] Shot compositions were prepared with bismuth shot and a tungsten buffer. To test the performance improvement of the tungsten / bismuth blend, variations of the same components were tested as follows:

[0070] Shotshell components:

[0071] Cheddite 12 ga 2¾″ Hull

[0072] 25.5 grains St. Marks OBP 473 powder

[0073] Gualandi 42 mm Cushioned Wad

[0074] 1-oz Copper Plated Bismuth Shot, #4 size

[0075] ½ oz Tungsten Shot (TSS), #9 size

[0076] 6 petal crimp, Roll Finished with #2 12 ga die

[0077] Crimp Depth of 0.050″

[0078] Trial 1: The tungsten was loaded first, at the bottom of the shot column, followed by the Bismuth being directly placed on top of the tungsten shot.

[0079] Trial 2: The bismuth shot was loaded first, at the bottom of the shot column, followed by the Tungsten being directly placed on top of the bismuth shot.

[0080] Trial 3: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the bismuth loaded at the top of the shot column.

[0081] Trial 4: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick cork cushion, followed by the bismuth loaded at the top of the shot column.

[0082] Trial 5: The bismuth shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the tungsten loaded at the top of the shot column.

[0083] Trial 6: The bismuth shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick cork cushion, followed by the tungsten loaded at the top of the shot column.

[0084] Trial 7: The bismuth shot was loaded first, at the bottom of the shot column followed by the tungsten placed directly on top of the bismuth. The shell was subjected to vibration in a similar manner to the aforementioned design using the organic buffer.

[0085] Performance of the shotshells was tested for pattern efficiency by firing on a target at 50 yards, with the data presented below in Table 2. Pattern efficiency was calculated in the same manner as Example 1.TABLE 2Pattern Efficiency with Tungsten Buffer at 50 YardsBiTungstenPrototype 359 Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS Bottom49.439.954.64Cork SpacerBismuth TopTrialTSS Top50.645.953.16Cork SpacerBismuthBottomTrialTSS Bottom46.143.947.33Felt SpacerBismuth TopTrialTSS Top Felt55.150.757.55SpacerBismuthBottomTrialTSS Bottom4740.550.51Bismuth TopTrialTSS Top48.245.349.82BismuthBottomTrialTSS +4836.554.27BismuthMixed

[0086] The data suggests that the improvements in the pattern yield benefit not only to the increased pattern efficiency of the bismuth and tungsten pellets without an organic buffer when compared to an all bismuth shell loaded with the same wad. By selecting a wad with a cushion section that allows for minimal height adjustment upon closure, the shell can be assembled in such a fashion that prevents migration of pellets to the top or bottom of the shot column as the closure forces effectively lock the pellets within the column in place. The benefit in using such a technology allows for the shooter to achieve increased range at longer distances due to the significant increase in density of tungsten (which measures anywhere from 12-19 g / cc) when compared to Bismuth (typically 9-10 g / cc).Example 3—Shot Composition with Bismuth Shot and Walnut and Tungsten Buffer

[0087] Shotshells similar to Example 2 were prepared but with a combination of the two buffer technologies, plant-based buffer and the high density tungsten buffer. The combined buffer resulted in slightly higher pattern efficiencies as compared to the pattern efficiencies of the tungsten only buffer. The results are presented in Table 3.TABLE 3Pattern Efficiency with Walnut and Tungsten Buffer at 50 YardsBiTungstenPrototype 359 w / Organic Buffer Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS + Buffer50.941.156.24Bottom CorkSpacer BismuthTopTrialTSS + Buffer51.947.054.46Top CorkSpacer BismuthBottomTrialTSS + Buffer47.144.948.43Bottom FeltSpacer BismuthTopTrialTSS + Buffer56.351.858.85Top Felt SpacerBismuthBottomTrialTSS + Buffer48.441.752.01BottomBismuth TopTrialTSS + Buffer49.546.551.12Top BismuthBottomTrialTSS + Buffer +49.437.655.87Bismuth MixedOther Embodiments

[0088] It should be apparent that the foregoing relates only to the preferred embodiments of the present invention and that numerous changes and modifications may be made herein without departing from the spirit and scope of the invention as defined by the following claims and equivalents thereof.

Examples

example 1

Bismuth Shot with Walnut Shell Buffer

[0045]A shotshell comprising bismuth shot and walnut shell buffer was prepared. The components of the shotshell were as follows:[0046]Cheddite 12 ga 2¾″ Hull[0047]25.5 grains St. Marks OBP 473 powder[0048]Gualandi 42 mm Cushioned Wad[0049]1¼ oz Copper Plated Bismuth Shot, #4 size[0050]22 grains of walnut shell buffer (about 0.05 ounces), 40 / 100 mesh, graphite coated[0051]6 petal crimp, Roll Finished with #2 12 ga die[0052]Crimp Depth of 0.050″

[0053]A non-buffered shotshell was also prepared as a control using the same components and assembly method but without the buffer.

[0054]A test was conducted using a single block of ballistic gelatin and fired at a measured distance of 30 yards. A steel plate covered one half of the gel block and the non-buffered shell was fired. The steel plate was then placed over the previously fired half and shot at the same distance within 1 minute of the first shot. The distance of penetration of the pellets that struc...

example 2

Bismuth Shot with Tungsten Buffer

[0069]Shot compositions were prepared with bismuth shot and a tungsten buffer. To test the performance improvement of the tungsten / bismuth blend, variations of the same components were tested as follows:

[0070]Shotshell components:[0071]Cheddite 12 ga 2¾″ Hull[0072]25.5 grains St. Marks OBP 473 powder[0073]Gualandi 42 mm Cushioned Wad[0074]1-oz Copper Plated Bismuth Shot, #4 size[0075]½ oz Tungsten Shot (TSS), #9 size[0076]6 petal crimp, Roll Finished with #2 12 ga die[0077]Crimp Depth of 0.050″[0078]Trial 1: The tungsten was loaded first, at the bottom of the shot column, followed by the Bismuth being directly placed on top of the tungsten shot.[0079]Trial 2: The bismuth shot was loaded first, at the bottom of the shot column, followed by the Tungsten being directly placed on top of the bismuth shot.[0080]Trial 3: The tungsten shot was loaded first, at the bottom of the shot column, followed by a ⅛″ thick felt cushion, followed by the bismuth loaded ...

example 3

Shot Composition with Bismuth Shot and Walnut and Tungsten Buffer

[0087]Shotshells similar to Example 2 were prepared but with a combination of the two buffer technologies, plant-based buffer and the high density tungsten buffer. The combined buffer resulted in slightly higher pattern efficiencies as compared to the pattern efficiencies of the tungsten only buffer. The results are presented in Table 3.

TABLE 3Pattern Efficiency with Walnut and Tungsten Buffer at 50 YardsBiTungstenPrototype 359 w / Organic Buffer Pattern Analysis @ 50 YardsPellet#9 PelletTotal #TotalBismuthTungstenCountCountPelletsPercentagePercentagePercentage148273421TrialTSS + Buffer50.941.156.24Bottom CorkSpacer BismuthTopTrialTSS + Buffer51.947.054.46Top CorkSpacer BismuthBottomTrialTSS + Buffer47.144.948.43Bottom FeltSpacer BismuthTopTrialTSS + Buffer56.351.858.85Top Felt SpacerBismuthBottomTrialTSS + Buffer48.441.752.01BottomBismuth TopTrialTSS + Buffer49.546.551.12Top BismuthBottomTrialTSS + Buffer +49.437.655.87...

Claims

1. A shot composition comprising a plurality of shot pellets and a buffer, wherein the buffer comprises a plurality of pieces of plant material.

2. The shot composition of claim 1, wherein the plant material comprises nut shell or nut hull.

3. (canceled)4. The shot composition of claim 2, wherein the plant material comprises walnut shell or walnut hull.

5. The shot composition of claim 1, wherein the plant material comprises corn cob.

6. (canceled)7. The shot composition of claim 1, wherein the plurality of pieces of plant material have an average diameter of from about 0.1 mm to about 1 mm.

8. (canceled)9. The shot composition of claim 1, wherein the plurality of pieces of plant material have an average volume per piece of from about 0.0005 mm3 to about 0.5 mm3.

10. The shot composition of claim 1, wherein the plurality of shot pellets comprise lead, steel, bismuth, tin or zinc.

11. The shot composition of claim 10, wherein the plurality of shot pellets comprise bismuth.

12. (canceled)13. (canceled)14. The shot composition of claim 11, wherein the plurality of shot pellets are copper plated.

15. (canceled)16. (canceled)17. The shot composition of claim 4, wherein the plurality of pieces of plant material comprising walnut shell or walnut hull are coated with a coating comprising graphite.

18. (canceled)19. (canceled)20. The shot composition of claim 7, wherein the plurality of shot pellets have a substantially uniform diameter of from about 2 mm to about 5 mm.

21. (canceled)22. The shot composition of claim 1, wherein the ratio of the average diameter of the plurality of pieces of plant material to the average diameter of the plurality of shot pellets is from about 1:5 to about 1:50.

23. The shot composition of claim 1, wherein the ratio of the total weight of the plurality of pieces of plant material to the total weight of the plurality of shot pellets is from about 1:5 to about 1:100.

24. (canceled)25. (canceled)26. The shot composition of claim 1, wherein the buffer is mixed among the plurality of shot pellets.

27. (canceled)28. A shotgun shell assembly comprising a cartridge loaded with a shot composition of claim 1.

29. (canceled)30. The shotgun shell assembly of claim 28, further comprising gunpowder disposed within the cartridge near a first end of the cartridge and wherein the shot composition is disposed within the cartridge near a second, opposite end of the cartridge,wherein the buffer is mixed among the plurality of shot pellets, andwherein the concentration of the buffer is greater in the shot composition proximal to the gunpowder and lesser in the shot composition distal to the gunpowder.

31. A shot composition comprising:a first plurality of shot pellets comprising tungsten, anda second plurality of shot pellets,wherein the second plurality of shot pellets have an average size larger than the average size of the first plurality of shot pellets, andwherein the second plurality of shot pellets have an average hardness less than the average hardness of the first plurality of shot pellets.

32. The shot composition of claim 31, wherein the first plurality of shot pellets are composed of at least 90 wt % tungsten or at least 90 wt % of a tungsten alloy, wherein the tungsten alloy comprises at least 50 wt % tungsten.

33. The shot composition of claim 32, wherein the second plurality of shot pellets comprise lead, steel, bismuth, tin or zinc.

34. The shot composition of claim 33, wherein the second plurality of shot pellets comprise bismuth.

35. The shot composition of claim 34, wherein the second plurality of shot pellets are composed of at least 90 wt % bismuth or at least 90 wt % of a bismuth alloy, wherein the bismuth alloy comprises at least 50 wt % bismuth.

36. (canceled)37. (canceled)38. (canceled)39. The shot composition of claim 31, wherein the first plurality of shot pellets are copper plated and / or the second plurality of shot pellets are copper plated.

40. (canceled)41. (canceled)42. (canceled)43. (canceled)44. (canceled)45. (canceled)46. (canceled)47. (canceled)48. The shot composition of claim 31, further comprising a buffer, wherein the buffer comprises a plurality of pieces of plant material.

49. The shot composition of claim 48, wherein the plant material is walnut shells or walnut hulls.

50. (canceled)51. A shotgun shell assembly comprising a cartridge loaded with a shot composition of claim 31.

52. (canceled)53. The shotgun shell assembly of claim 51, further comprising gunpowder disposed within the cartridge near a first end of the cartridge and wherein the shot composition is disposed within the cartridge near a second, opposite end of the cartridge,wherein the first plurality of shot pellets are mixed among the first plurality of shot pellets, andwherein the concentration of the first plurality of shot pellets is greater in the shot composition proximal to the gunpowder and lesser in the shot composition distal to the gunpowder.

54. The shotgun shell assembly of claim 51, wherein first plurality of shot pellets and the second plurality of shot pellets are separated in the cartridge by a spacer.

55. The shotgun shell assembly of claim 54, wherein the spacer is a felt cushion or a cork cushion.

56. (canceled)57. (canceled)

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