Feed stop for ammunition magazine

Abstract

An ammunition magazine for a gun includes a magazine body defining an interior space in which a plurality of cartridges is receivable, a follower in the interior space configured to bias the cartridges toward an upper end of the magazine body, a feed lip at the upper end of the magazine body configured to engage a topmost cartridge received in the interior space, and a movable feed stop on the magazine body configured to press the topmost cartridge against the feed lip and thereby prevent the plurality of cartridges from being pushed out of the top of the magazine by the follower.

What is claimed is: 
     
         1 . An ammunition magazine for a gun, comprising:
 a magazine body defining an interior space in which a plurality of cartridges is receivable;   a follower in the interior space configured to bias the cartridges toward an upper end of the magazine body;   a feed lip at the upper end of the magazine body configured to engage a topmost cartridge received in the interior space; and   a movable feed stop on the magazine body configured to press the topmost cartridge against the feed lip.   
     
     
         2 . The ammunition magazine of  claim 1 , wherein the feed stop is movable between:
 an extended position wherein the feed stop engages the topmost cartridge to press the topmost cartridge against the feed lip, and   a depressed position wherein the feed stop does not engage the topmost cartridge.   
     
     
         3 . The ammunition magazine of  claim 2 , wherein the feed stop is biased toward the extended position. 
     
     
         4 . The ammunition magazine of  claim 1 , wherein the feed stop is configured to hold the topmost cartridge against the feed lip until an advancing bolt of the gun pushes the topmost cartridge toward a firing chamber of the gun. 
     
     
         5 . The ammunition magazine of  claim 1 , wherein the feed stop exerts a pressing force on the topmost cartridge that is less than a pushing force exerted on the cartridge by an advancing bolt of the gun during cycling of the gun such that the topmost cartridge can be pushed out of contact with the feed lip and into a firing chamber of the gun by the bolt. 
     
     
         6 . The ammunition magazine of  claim 4 , wherein the bolt is larger than a diameter of the topmost cartridge. 
     
     
         7 . The ammunition magazine of  claim 1 , wherein the feed stop is on a side interior surface of the upper end of the magazine body spaced from the feed lip. 
     
     
         8 . The ammunition magazine of  claim 1 , wherein the feed stop is on a side of the magazine opposite the feed lip. 
     
     
         9 . The ammunition magazine of  claim 1 , wherein:
 the upper end of the magazine body includes first and second opposing sidewalls;   the feed lip is at an upper end of the first sidewall; and   the feed stop is pivotably connected to the second sidewall.   
     
     
         10 . The ammunition magazine of  claim 9 , wherein the feed stop is spring biased toward an extended position wherein the feed stop engages the topmost cartridge to press the topmost cartridge against the feed lip. 
     
     
         11 . The ammunition magazine of  claim 9 , wherein the feed lip is spaced from the second sidewall by a distance greater than a diameter of the topmost cartridge. 
     
     
         12 . The ammunition magazine of  claim 11 , wherein the plurality of cartridges is receivable in the interior space in a single stack orientation. 
     
     
         13 . The ammunition magazine of  claim 1 , wherein:
 the upper end of the magazine body includes first and second opposing sidewalls, a rear wall extending between the first and second opposing sidewalls, and a gap in the rear wall through which an advancing bolt of the gun can pass during cycling of the gun; and   the gap has a width that is greater than a diameter of the topmost cartridge.   
     
     
         14 . The ammunition magazine of  claim 1 , wherein:
 the feed stop is pivotably mounted to the magazine body;   the feed stop is biased upwardly toward engagement with the topmost cartridge; and   the feed stop is configured to pivot downwardly out of engagement with the topmost cartridge as an advancing bolt of the gun pushes the topmost cartridge toward a firing chamber of the gun.   
     
     
         15 . The ammunition magazine of  claim 13 , wherein the feed stop is configured to pivot downwardly out of engagement with the topmost cartridge in response to the bolt or a bolt carrier contacting the feed stop and pushing the feed stop downwardly as the bolt pushes the topmost cartridge longitudinally forward toward the firing chamber. 
     
     
         16 . The ammunition magazine of  claim 1 , wherein:
 the upper end of the magazine body includes first and second opposing sidewalls;   the feed lip is at an upper end of the first sidewall;   the feed stop is pivotably connected to the second sidewall;   the feed stop is biased upwardly toward engagement with the topmost cartridge;   the second sidewall includes a guide slot in which a portion of the feed stop is slidably receivable; and   the feed stop is configured to pivot down into the guide slot and disengage the topmost cartridge as an advancing bolt of the gun pushes the topmost cartridge toward a firing chamber of the gun.   
     
     
         17 . The ammunition magazine of  claim 1 , wherein:
 the magazine is a drum magazine comprising a drum portion and a feed tower portion; and   the plurality of cartridges is receivable in the interior space in a single stack orientation.   
     
     
         18 . An ammunition magazine for a gun, comprising:
 a magazine body defining an interior space in which a plurality of cartridges is receivable;   a follower in the interior space configured to bias the cartridges toward an upper end of the magazine body;   a feed lip at the upper end of the magazine body configured to engage a topmost cartridge received in the interior space; and   a feed stop on a sidewall of the magazine body opposite the feed lip configured to hold the topmost cartridge against the feed lip until an advancing bolt of the gun pushes the topmost cartridge toward a firing chamber of the gun.