Arcuate magazine for a firearm and a method for making the same

Abstract

An arcuate magazine for a firearm, such as a rifle or carbine, which has a keyway and follower assembly for delivering rounds of ammunition one at a time to the firing area of the firearm and which may be fabricated from a single piece of metal and have a smooth interior free of welds and rough spots. The invention also includes a method of making such a magazine which includes the steps of deep drawing and wiping the magazine body under substantial pressure using a progressive die having numerous stations.

Description

PRIORITY CLAIM[0001]This application claims priority from U.S. Provisional Patent Application Ser. No. 60 / 922,104 filed 6 Apr. 2007, entitled METHOD TO DRAW AND FORM A CURVED FIREARM CARTRIDGE MAGAZINE BODY WITH A KEYWAY.BACKGROUND AND SUMMARY OF THE INVENTION[0002]This invention relates to a cartridge magazine for a firearm and a method for making such a magazine, and is more particularly related to such a magazine and method wherein the magazine is arcuate in shape and has a body preferably formed from a single piece of metal.[0003]Such a magazine is used to contain ammunition, such as a series of cartridges, which are fed one at a time by spring means into a firing chamber of a weapon. The spring means maintains pressure on the ammunition to force each cartridge in to the firing chamber, and when spent to deliver the next round into firing position.[0004]An example of a firearm using a magazine is the M16 rifle or carbine, which has become a standard rifle in the United States we...

AI Technical Summary

Benefits of technology

[0020]It is the object of the invention to provide an arcuate magazine for a rifle or carbine of the character described.

[0020]It is the object of the invention to provide an arcuate magazine for a rifle or carbine of the character described.

[0026]Another object is to provide a method for fabricating an arcuate magazine which is drawn and formed into a blank having a central keyway, sides depending from the keyway and edges remote from the keyway for welding the blank closed.

[0023]Another object is to provide an arcuate magazine for a weapon which may be heat treated with nitride or the like to provide a hardened finish.

[0027]Another object is to provide a method for fabricating a blank for an arcuate magazine having a keyway which is formed and drawn by means of high pressure applied to both sides of the blank.

[0026]Another object is to provide a method for fabricating an arcuate magazine which is drawn and formed into a blank having a central keyway, sides depending from the keyway and edges remote from the keyway for welding the blank closed.

[0027]Another object is to provide a method for fabricating a blank for an arcuate magazine having a keyway which is formed and drawn by means of high pressure applied to both sides of the blank.

[0027]Another object is to provide a method for fabricating a blank for an arcuate magazine having a keyway which is formed and drawn by means of high pressure applied to both sides of the blank.

Problems solved by technology

Preferably, such a magazine is fabricated from steel rather than plastic or aluminum, as the magazine is subject to heat and substantial stress when it is used in the field.

These operations were crucial, because breaking, bending or malformation of the welds or misalignment of the parts could cause the cartridges to become canted or in extreme cases to fall from the magazine, making the use of the weapon ineffective or dangerous in the field.

Correct formation of the keyway is critical: a magazine with a misshaped keyway could make the magazine unuseable as the magazine could not be installed in the receiver lower.

Many references in the prior art deal with magazines for handguns, and these magazines are not typical of magazines for rifles or carbines, which are subject to great field stress and situations where the very life of the user depends upon the effectiveness of the weapon.

If inadequate pressure is applied, the keyway fails to form.

If excess pressure is applied, the metal tears.

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