Ammunition comprising a base and an insert

A two-piece ammunition case design with a base and insert simplifies manufacturing and enhances stability, addressing weight and tearing issues, ensuring accurate projectile guidance and high-pressure performance.

WO2026082964A1PCT designated stage Publication Date: 2026-04-23LAVERGNE VINCENT
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Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
LAVERGNE VINCENT
Filing Date
2025-10-17
Publication Date
2026-04-23

AI Technical Summary

Technical Problem

Existing ammunition designs face challenges with complex manufacturing, weight constraints, and potential tearing of the cartridge case due to deformation stresses during firing, particularly when using a degradable sabot and a nozzle throat configuration.

Method used

The ammunition is designed with a two-piece case comprising a base and an insert, where the propellant charge is integrated before assembly, and the case is crimped or locked together using various methods to ensure stability and coaxiality, including external and internal locking mechanisms.

Benefits of technology

This configuration simplifies manufacturing, reduces weight, and enhances the stability of the cartridge case during firing, ensuring accurate projectile guidance and reducing the risk of tearing, while maintaining high-pressure performance.

✦ Generated by Eureka AI based on patent content.

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Abstract

The present invention relates to ammunition comprising a projectile (1), a propellant charge (3) and a priming device (5), held together by a cartridge case, the cartridge case forming a nozzle, a nozzle throat, a combustion chamber (4j) and a primer channel. The ammunition is characterized in that the cartridge case consists of at least two parts: a base (4b) and an insert (4a), said parts being assembled together once the propellant charge (3) has been integrated into the combustion chamber (4j).
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Description

[0001] TITLE: Ammunition comprising a base and an insert

[0002] FIELD OF INVENTION

[0003] The present invention relates to ammunition comprising a base and an insert. Such ammunition is particularly suitable for use in firearms.

[0004] STATE OF THE ART

[0005] In the firearms industry, regardless of caliber or application, there is always a strong preference for solutions that facilitate the handling of consumable components with each shot. This issue is paramount in the arms industry because it impacts both operator safety and weapon performance. This explains why pre-assembled ammunition has become the standard for the vast majority of applications.

[0006] According to a prior art example, as shown in Figure 1, an assembled cartridge consists of a cartridge case 4, a primer 5, a propellant charge 3a, 3b, and a projectile 1. The role of the cartridge case 4 is to maintain the integrity of all the components necessary for firing into a compact unit. The shape of the cartridge case 4 also fulfills several functions, including: allowing the cartridge to be positioned in the barrel before firing, ensuring the barrel is sealed during firing, providing protection for the propellant charge 3a, 3b from the environment during storage or handling, and guaranteeing the possibility of extracting the cartridge or firing debris after firing. Consequently, the shape of a cartridge case 4 is relatively fixed, as these constraints have been known and resolved for over a century.

[0007] Typically, a high-pressure 4-round cartridge case is made from a single piece of brass or steel through a multi-stage stamping process. However, weight constraints for new ammunition are such that multi-piece, permanently assembled 4-round cartridge case solutions are gradually emerging, as demonstrated by True Velocity's US patent 9,518,810 and Sig Sauer's US patents 10,866,072 and 11,067,370. It is important to note that both of these solutions were proposed in response to the US Army's NGSAR and NGSW requests for proposals, which aimed to provide a significant performance increase for weapon and ammunition combinations compared to existing solutions.

[0008] The solutions proposed during these calls for tenders clearly exposed the limitations of the approach of improving the performance of a weapon and ammunition combination by simply increasing the service pressure. It was therefore necessary to conduct further internal ballistic studies, which led to the discovery of the solutions protected by patents FR 22 04 908 and FR 22 04 909. The general principle of these solutions can also be illustrated by Figure 1.

[0009] With reference to Figure 1, patents FR 22 04908 and FR 22 04909 highlight a sub-caliber ammunition solution particularly suited to the constraints and needs specific to small and medium caliber firearms. Indeed, this solution incorporates the combination of two distinctive elements of the innovations, namely:

[0010] - The presence of a nozzle 4k, separating the combustion chamber 4j from the barrel, consisting of a convergent section, a nozzle throat 4h, and a divergent section, allows for a substantial increase in the velocity of the propellant gases inside the barrel as soon as the throat 4h is primed. This reduces the pressure on the internal walls of the barrel while maximizing the thrust of the propellant gases on the projectile 1, even though it is close to the muzzle despite the barrel's length.

[0011] - The use of a degradable sabot 2, combined with the use of a tapered barrel, maximizes the thrust surface at the beginning of the internal ballistics while allowing direct guidance of the projectile 1 inside the barrel near its muzzle. This increases the acceleration of the projectile 1 by maintaining moderate propellant gas pressure in the first part of the barrel while retaining the use of rifling in the barrel near the muzzle to stabilize the projectile 1.

[0012] However, this same figure also presents two design difficulties:

[0013] - A 4-inch socket has the disadvantage of being relatively heavy in addition to being particularly complex (and therefore expensive) to make.

[0014] - Filling the combustion chamber 4j with the propellant charge 3a, 3b requires the propellant to pass through the throat of the nozzle 4h or through the primer channel 4f. This would imply that the propellant charge 3a, 3b would be loaded in the form of very small granules in order to be able to enter despite the restricted cross-section of each of these passages, or flowed through the throat of the nozzle 4h in the form of a liquid (more or less viscous) so that the propellant charge 3a, 3b can fill the volume of the chamber.

[0015] However, certain constraints make this manufacturing complexity legitimate.

[0016] In particular, the need for good coaxiality between the projectile 1, the sabot 2, and the barrel during the forcing of the assembly consisting of the projectile 1 and sabot 2 into the barrel—that is, during the transition from the guidance of the sabot 2 by the socket 4 to the guidance of the sabot 2 by the barrel at the very beginning of the internal ballistic phase. This step is crucial when using a degradable sabot 2, as a second forcing operation occurs when the projectile 1 engages the rifling of the barrel.

[0017] Furthermore, during firing, the lateral walls of the combustion chamber 4j are subjected to tension by the pressure of the gases on the nozzle converging 4k and on the base of the cartridge case 4. This stress is also present in ammunition with a conical cartridge case 4 or when the headspace is created by a shoulder (generally conical) between the large-diameter portion of the cartridge case 4, which serves as a reservoir for the propellant charge 3a, 3b, and the neck retaining the projectile 1. It should be noted, however, that this stress is even more pronounced when the diameter of the neck of the cartridge case 4 is small. Beyond the problem of longitudinal deformation of the cartridge case 4 during firing, it is indeed a problem of cartridge case 4 tearing, and therefore a breach of the chamber seal, that can result from improper system design.

[0018] SUMMARY OF THE INVENTION

[0019] The purpose of this document is to resolve the aforementioned problems of the state of the art.

[0020] To this end, the invention relates to a munition comprising a projectile, a propellant charge and a priming device held together by a case, the case forming a nozzle, a nozzle neck, a combustion chamber and a primer channel, characterized in that the case is made up of at least two parts: a base and an insert, said parts being assembled together after the integration of the propellant charge inside the combustion chamber.

[0021] The problems raised in the prior art have indeed been solved by splitting the casing into two pieces (a base and an insert) which are permanently assembled after the propellant charge has been placed in the munition.

[0022] According to other advantageous aspects of the invention, the munition comprises one or more of the following features taken individually or in all technically possible combinations: - the side wall of the combustion chamber is formed by an extended part of the base, the combustion chamber being closed by the insert;

[0023] - the crimping of the base onto the insert is achieved by deforming a collar of the base inside a groove of the insert by means of a crimping die, the insert being pressed against the base by means of an insert positioner;

[0024] - an external seal is placed in the groove of the insert following crimping, said external seal bearing in a chamber of the barrel during firing;

[0025] - the side wall of the combustion chamber is formed by an extended part of the insert, the combustion chamber being closed by the base by means of the interlocking of two complementary portions;

[0026] - the assembly of the base on the insert is secured by the presence of an internal lock put in place by means of a spreader which deforms the internal lock when it is extracted through the primer channel;

[0027] - the insert is made by assembling the nozzle inside a socket body;

[0028] - the projectile and its sabot are positioned inside a barrel by means of cylindrical or slightly conical bearing surfaces forming front and rear contacts between the insert and the barrel;

[0029] - the ammunition is positioned longitudinally in the barrel;

[0030] - the longitudinal positioning of the ammunition in the barrel is ensured by a conicity of the front or rear contact and the compression of the link between the insert and the base by a breechblock;

[0031] - the ammunition is positioned longitudinally in the barrel;

[0032] - the longitudinal positioning of the ammunition inside the barrel is achieved by means of a rebate contact between the base and the barrel.

[0033] In addition, the invention relates to a method for manufacturing ammunition comprising an internal nozzle separating the combustion chamber from the barrel where the thrust on the projectile occurs. This particular configuration offers advantages in terms of barrel operating pressure but poses certain problems for ammunition manufacturing. Indeed, the presence of a nozzle throat, separating the combustion chamber from the barrel, makes filling the cartridge case with propellant to form the propellant charge particularly complex.

[0034] In addition, to maximize the effects of the nozzle, the use of an undersized projectile is recommended. This implies that the projectile's guidance through the barrel is achieved via an intermediate component or, at a minimum, the use of a projectile with deformation properties that allow its diameter to decrease as it travels down the barrel. In both cases, the projectile's position relative to the barrel prior to firing is a crucial parameter determining the accuracy of the entire barrel-ammunition assembly, especially when the projectile is stabilized by its rotation using rifling within the barrel.

[0035] To allow the integration of a neck and nozzle inside a cartridge case, it may be advantageous for the latter to be made in the form of an insert made of relatively resistant and refractory material, and taking place, at least partially, inside the base.

[0036] In one embodiment, the short insert is placed at the front of the long base and crimped to the long base after the latter has received the propellant charge. Ideally, to ensure the projectile is centered in the barrel before firing, the headspace of the cartridge should pass through the short insert. This configuration also offers the advantage of allowing the force resulting from the pressure inside the combustion chamber to act directly on the barrel during firing. The seal between the short insert and the long base is achieved by energizing the combustion chamber, which will tend to push outward and crush the front portion of the long base against the internal walls of the barrel chamber.If there is still concern about the strength of the assembly between the short insert and the long base, it is possible to integrate an external lock into the assembly so as to make it geometrically impossible to separate the short insert from the long base inside the chamber of the barrel.

[0037] In another embodiment, a cartridge case open at both ends has an internal shoulder allowing the placement of a short insert from the rear end. The projectile is then placed inside the short insert, and the sabot is cast between the short insert, optionally the cartridge case body, and the projectile, thus closing the front part of the cartridge. The propellant charge is placed inside the combustion chamber before the latter is closed by a short base that receives the primer.

[0038] The combustion chamber is sealed from the rear by means of a short metal base surrounding the outside of the cartridge case body and secured by crimping. Ideally, an internal locking device in the form of a conical spring washer can be placed inside the cartridge case body above the propellant charge. When the short base is installed, it pushes on the internal locking device until the conical shape of the washer reverses.

[0039] By extension of this latter method of manufacture, it is possibly possible to fuse the short insert and the socket body into a long insert provided that the material used is the same and that the process of obtaining this part involves plastic or metal injection.

[0040] It is important to note, however, that: while it remains possible to adapt the external closing and locking technique to a short base and a long insert, and conversely, the internal closing and locking technique to a long base on a short insert, these two configurations are governed by additional constraints.

[0041] Indeed, when the external locking pin is positioned very close to the case base, contact between the external locking pin and the chamber is quickly lost during cartridge extraction. This means the crimp must be able to withstand greater tensile stresses between the case base and the insert. One solution to mitigate this problem is to adopt a sufficiently tapered overall design for the cartridge case to minimize the risk of the case sticking in the chamber during firing.

[0042] Conversely, if the internal locking mechanism is located on the nozzle side, it is important to consider that the nozzle geometry must incorporate a convergent section, a throat, and a divergent section. To accommodate these two aspects, two solutions can be implemented: Either, at a minimum, the convergent and throat functions are located on the internal locking mechanism itself, rather than on the insert, allowing for installation using a spreader. Or, the internal locking mechanism relies on reversing the taper of the internal locking mechanism during crimping, with the constraint that the internal diameter of the locking mechanism must be greater than the maximum diameter of the nozzle's convergent section.

[0043] DESCRIPTION OF THE FIGURES

[0044] The invention will become clearer upon reading the following description, given solely by way of non-limiting example and with reference to the drawings in which:

[0045] - [Fig.1] Figure 1 is a schematic view of a munition according to the state of the art;

[0046] - [Fig.2] [Fig.3] [Fig.4] [Fig.5] Figures 2 to 5 are different views of a munition according to a first embodiment of the invention; and

[0047] - [Fig.6] [Fig.7] [Fig.8] [Fig.9][Fig.10] Figures 6 to 10 are different views of a munition according to a second embodiment of the invention.

[0048] - [Fig. 11] Figure 11 is a schematic view of a munition according to an embodiment adapted to the architecture of large-caliber munitions. DETAILED DESCRIPTION OF THE INVENTION

[0049] As illustrated in the various attached figures, the munition according to the invention has a two-piece case 4: a base 4b, 4d and an insert 4a, 4b. These parts are permanently assembled after the propellant charge 3 has been placed in the munition.

[0050] The base 4b, 4d is the rear portion of the cartridge case 4, which rests against the breechblock 9 of the weapon when the ammunition is chambered in the barrel 10 (visible in Figures 5 and 9). Given the pressures involved during firing, the material used for the base 4b, 4d of the ammunition is a metal combining good mechanical strength with a high capacity for deformation without breakage. Historically, bronze has been the preferred material for manufacturing cartridge cases 4 due to its malleability during the manufacturing process and during firing. However, it is not uncommon to find steel cartridge cases 4 when the strength requirement for the base 4b, 4d or the cartridge case walls is high, or aluminum cartridge cases 4 when the mass requirement for the ammunition is greater (aeronautical applications).

[0051] The insert 4a, 4b is the part forming the front of the cartridge case 4 and including the nozzle 4k as described in patent applications FR 22 04909 and FR 22 04908. Although the pressure and temperature internal to the combustion chamber 4j are applied to the internal walls of the insert 4a, 4c, the choice of material for the latter is quite broad insofar as it is a relatively massive part supported by the chamber of the barrel 10. Thus, it is possible to use various metals (steel, bronze or aluminum), but also certain polymers, either in a simple form or in a composite (with short fibers or ceramic microbeads), or even a pure ceramic, depending on the weight constraints of the assembled ammunition and the ease of their production.Applying a surface treatment, such as ceramic paint or a carbon coating in the form of graphite or diamond, to the internal faces of insert 4a, 4c may be useful to limit abrasion of the nozzle throat 4h during firing. Similarly, a surface treatment on the external walls of insert 4a, 4c, such as a lacquer, may be useful to reduce friction with the chamber of barrel 10 during loading and ejection of ammunition into barrel 10.

[0052] The ammunition designer is under no obligation to choose the same material for the base (4b, 4d) and the insert (4a, 4c). However, they do not make random combinations but take into account certain constraints, such as the chemical and electrochemical compatibility between the materials used for the base (4b, 4d), the insert (4a, 4c), and the propellant used for the propellant charge (3, 3a, and 3b). This is particularly important to prevent corrosion at the interface between the two components or chemical attack on either component by acidic substances released by the propellant in the case of prolonged storage or under poor conditions. Similarly, certain choices are dictated by the need for dimensional stability characteristics under heat, humidity, etc., to guarantee the integrity of the ammunition during storage and handling in uncontrolled environments.

[0053] However, it is necessary to address the problems that arise, or are exacerbated, by the adopted modification. To do this, it is necessary to isolate the issues and their associated contributing factors, and thus define the conditions under which the issues are resolved.

[0054] From a safety standpoint, the critical point concerns the risk of tearing due to the deformation stresses of the cartridge case during firing. To address this, ammunition designers have two options:

[0055] - One possibility, corresponding to the first embodiment illustrated in figures 2 to 5, would be to combine the use of a long base 4b with a method of assembling the insert 4a on the long base 4b allowing a relative longitudinal movement between the two parts during firing (dynamic rebate) while ensuring the cohesion of the socket 4 for the ejection operation.

[0056] Another possibility, corresponding to the second embodiment illustrated in Figures 6 to 10 and 11, consists of placing the rebate (and therefore the seal) on the base 4d of the cartridge case 4 by adopting a reinforced rim base geometry. The advantage of this solution is that the weapon's operation is not affected by variations in the length of the cartridge case 4 during firing. This solution is known for applications in weapons whose locking system operates by orthogonal movement of the bolt relative to the axis of the barrel 10 (falling block locking as well as revolver-type mechanisms).

[0057] The requirement for coaxiality between the projectile 1 and its sabot 2 relative to the barrel 10, prior to firing, necessitates minimizing the number of intermediate parts used to position the projectile 1 within the chamber of the barrel 10. Thus, although it is possible to adopt a cartridge case design in which the insert 4a is not directly integrated into the short base 4d by using a third intermediate part forming a cartridge case body 4i, it is preferable for the ammunition designer to minimize the number of intermediate components between the projectile 1 and the barrel 10 before firing. The ammunition design meeting these criteria consists of replacing the projectile 1 of a larger caliber round with an assembly comprising the short insert 4a, the new projectile 1, and the degradable sabot 2.In this case, it is preferable that the positioning of the short insert 4a inside the barrel 10 be achieved through a complementary relationship between the taper of the barrel chamber 10b and that of the short insert 4a, combined with a compressive stress on the short insert 4a due to its contribution to the headspace via the front contact 10a, as illustrated in Figure 5. Therefore, the assembly method of the short insert 4a onto the long base 4b must take into account the need for elasticity along the axis of the barrel chamber 10 to allow for the absorption of dimensional variability in the ammunition through a "crushing" process. To this end, a groove is present on the outer wall of the short insert 4a and serves to accommodate the front end of the long base 4b during a two-stage crimping, as illustrated in Figures 3 and 4.Prior to crimping the short insert 4a onto the long base 4b, the front end of the long base 4b consists of a flared rim whose diameter is greater than the maximum diameter of the short insert 4a. The crimping is carried out using a die composed, on the one hand, of an insert positioner 7c (visible in figures 3 and 4), which pushes the short insert 4a against the front face of the long base 4b by means of a spring, and on the other hand of a crimping die 7b whose front face is chamfered so as to impose a plastic deformation of the flared portion of the long base 4b inside the groove of the short insert 4a. At the end of the die-forming movement, the long base 4b is compressed axially against the short insert 4a in order to confirm the plastic deformation of the portion used for crimping the long base 4b onto the short insert 4a.In the case of adopting a long base 4b with constant cylindrical section, it is possible to reverse the positioning of the crimping die 7b by placing it around the long base 4b and not around the short insert 4a.

[0058] Preferably, the positioning of the long insert 4c relative to the barrel 10 is ensured by distributing the contact along two short, cylindrical or slightly conical bearing surfaces 10c and 10d, positioned as far apart as possible along the axis of the barrel 10. To achieve this, it is advantageous for the walls of the combustion chamber 4j to be formed inside the long insert 4c and not within a long base 4b. In this case, the ammunition production cycle changes: the first step consists of centering the projectile 1 on the long insert 4c by means of a die into which the material forming the degradable sabot 2 will be injected. The second step consists of loading the propellant charge 3 into the combustion chamber 4j through the opening of the long insert 4c at the interface with the short base 4d. The third step consists of closing the combustion chamber 4j with the short base 4d by means of a crimp.The short base 4d may have been fitted with the primer 5 prior to this step, or the primer may be crimped onto the short base 4d at the end of the ammunition assembly. A finishing step may be added at the end of the manufacturing process to certify the ammunition's resistance to external moisture by applying lacquer to the crimp connections between the short base 4d and the long insert 4c, as well as between the short base 4d and the primer 5. Ideally, the injection points of the biodegradable sabot 2 are also deburred, followed by the application of a thin layer of lacquer to the front surface of the biodegradable sabot 2 to ensure a certain degree of ammunition stability under storage conditions.

[0059] To ensure the connection between the base 4b, 4d and the insert 4a, 4c, it may be useful to use an additional safety piece 6 to confirm the locking of the crimp, whether during extraction operations or during firing itself.

[0060] In cases where the chosen ammunition design relies on the external crimping of a long base 4b onto a short insert 4a, the crimping lock confirmation function can be achieved by means of an external seal 6a positioned in the groove formed by the plastic deformation of the flared section of the long base 4b during crimping. When the ammunition is chambered, this external seal 6a is pressed against the inner wall of the chamber of the barrel 10, preventing disassembly between the long base 4b and the short insert 4a during the extraction of a fired or unused round.

[0061] In cases where the chosen ammunition design relies on crimping a short base 4d onto a long insert 4c, the crimp locking function can be achieved by permanently deforming an internal locking 6b, potentially tulip-shaped, into the short base 4d in a manner similar to a blind rivet (also known as a pop rivet), through the primer channel 4f. In this case, as illustrated in Figure 7, preparing the short base 4d for crimping involves inserting the locking 6b into the base of the short base 4d and a spacer rod 8c for the locking 6b, which passes through the locking 6b and the channel connecting the primer pocket 4g to the combustion chamber 4j.The crimping is carried out by placing the short base 4d onto the long insert 4c, previously equipped with the propellant charge 3, by means of a base die 8b while the spacer 8c is held by a clamping device, as shown in figure 7. While the crimping dies 8a, 8b hold the short base 4d against the long insert 4c, the spacer 8c is completely withdrawn through the primer channel 4f which causes the locking pin (6b then 6c) to deform against the short base 4d until contact between the locking pin 6c and the long insert 4c is established as shown in figure 8, which makes the connection between the long insert 4c and the short base 4d impossible to disassemble. The pull on the spreader 8c is maintained until the latter has passed through the lock 6c, freeing the passage between the primer housing 4g and the combustion chamber 4j.The sealed munition can continue its manufacturing process by crimping the primer 5 into the primer housing 4g at the rear of the short base 4d and by creating an external seal using lacquer in the gap between the primer 5 and the short base 4d, between the short base 4d and the long insert 4c and on the degradable sabot 2.

[0062] Alternatively, as shown in Figure 11, and in order to adapt the configuration—short base 4d combined with a long insert 4c—to the ignition requirements of large-diameter ammunition such as tank rounds, it is possible to replace the use of a spacer 8c for locking the case closure assembly 4 with the use of a thread between the internal locking pin 6c and the tubular portion of the primer 5 containing the initiating charges 3c. In this case, the ammunition assembly procedure follows these steps:

[0063] - Introduction of the propellant charge 3, in the form of one or more sub-assemblies (monobloc of propellant 3a or fuel-jacketed cartridges containing a charge of grain powder 3b) conditioned in tubes allowing the passage of the tubular part of the primer 5, inside the combustion chamber 4j formed in the long insert 4c.

[0064] - Separate pre-assembly of the short base 4d with the internal lock 6c not crushed in position, held in place by the thread of the tubular part of the primer 5 containing the initiating charges 3c.

[0065] - Closure of the combustion chamber 4j by crimping the short base 4d onto the long insert 4c.

[0066] - Locking of the assembly by crushing the internal lock 6c against the short base 4d by means of the thread of the primer tube 5 and an indexing between the internal lock 6c and the short base 4d.

[0067] - Sealing of the primer 5 in the short base 4d by means of glue or by crimping by punching the short base 4d onto the primer 5.

[0068] It is also clear that the dimensions of at least one of the propellant charge components are larger than those of the nozzle throat 4h and the primer channel 4f. Therefore, introducing this charge either through the nozzle throat 4h or the primer channel 4f would not be possible.

Claims

DEMANDS 1. Munition comprising a projectile (1), a propellant charge (3) and a priming device (5) held together by a case (4), the case (4) forming a nozzle (4k), a nozzle neck (4h), a combustion chamber (4j) and a primer channel (4f), characterized in that the case (4) consists of at least two parts: a base (4b; 4d) and an insert (4a; 4c), said parts being assembled together after the integration of the propellant charge (3) inside the combustion chamber (4j).

2. Munition according to claim 1, characterized in that the side wall of the combustion chamber (4j) is formed by an extended part of the base (4b), the combustion chamber (4j) being closed by the insert (4a).

3. Ammunition according to claim 2, characterized in that the crimping of the base (4b) onto the insert (4a) is obtained by deforming a collar of the base (4b) inside a groove of the insert (4a) by means of a crimping die (7b), the insert (4a) being pressed against the base (4b) by means of an insert positioner (7c).

4. Munition according to claim 3, characterized in that an external seal (6a) is placed in the groove of the insert (4a) following crimping, said external seal (6a) bearing in a chamber of the barrel (10) during firing.

5. Munition according to claim 1, characterized in that the side wall of the combustion chamber (4j) is formed by an extended part of the insert (4c), the combustion chamber (4j) being closed by the base (4d) by means of the interlocking of two complementary portions.

6. Munition according to claim 5, characterized in that the assembly of the base (4d) on the insert (4c) is secured by the presence of an internal lock (6c) put in place by means of a spreader (8c) deforming the internal lock (6b) when it is extracted through the primer channel (4f).

7. Munition according to claim 5 or 6, characterized in that the insert (4c) is made by assembling the nozzle (4k) inside a cartridge case body (4i).

8. Munition according to any one of claims 1 to 7, characterized in that the projectile (1) and its sabot (2) are positioned inside a barrel (10) by means of cylindrical or slightly conical bearing surfaces forming front (10a; 10c) and rear (10b; 10d) contacts between the insert (4a; 4c) and the barrel (10).

9. Ammunition according to claim 8 characterized in that: - the munition is positioned longitudinally in the barrel (10); the longitudinal positioning of the munition in the barrel (10) is ensured by a conicity of the front contact (10a; 10c) or of the rear contact (10b; 10d) and the compression of the link between the insert (4a; 4c) and the base (4b; 4d) by a breech (9).

10. Ammunition according to claim 8, characterized in that: - the ammunition is positioned longitudinally in the barrel (10); - the longitudinal positioning of the munition inside the barrel (10) is obtained by means of a rebate contact (10f) between the base (4b; 4d) and the barrel (10).

11. Munition according to any one of claims 1 to 10, characterized in that the dimensions of at least one of the components of the propellant charge (3) are greater than those of the nozzle neck (4h) as well as those of the primer channel (4f).

12. Munition according to any one of claims 1 to 11, characterized in that the primer channel (4f) separates the combustion chamber (4j) from a primer housing (4g).

Citation Information

Patent Citations

  • title not available

    FR2204908A1

  • FR2204909A1

  • Multi-piece cartridge casing and method of making

    US10866072B2

  • Multi-piece cartridge casing and method of making

    US11067370B2

  • Polymer ammunition cartridge having a two-piece primer insert

    US9518810B1