Composite cartridge case

Abstract

A cartridge case has a heel element having a forward portion, a generally flat rear end portion, and a circumferential groove, having a generally radially extending rear face and a sloped forward face. A separate generally tubular sidewall, extends over the forward portion of the heel element and over the sloped forward face into the circumferential groove.

What is claimed is: 
     
         1 . A cartridge case comprising:
 a heel element having a forward portion, a generally flat rear end portion, and a circumferential groove, having a generally radially extending rear face and a sloped forward face;   a separate generally tubular sidewall, the rearward end portion of the sidewall extending over the forward portion of the heel element and over the sloped forward face into the circumferential groove.   
     
     
         2 . The cartridge case according to  claim 1  wherein the forward portion of the heel element is generally cup-shaped, comprising a wall that tapers toward its forward end. 
     
     
         3 . The cartridge case according to  claim 2  wherein the circumference of the wall tapers toward the forward end of the heel element. 
     
     
         4 . The cartridge case according to  claim 1  wherein the heel portion is made from a first metal or metal alloy and the tubular sidewall is made from a second metal or metal alloy. 
     
     
         5 . The cartridge case according to  claim 4  wherein the heel portion is made from stainless steel. 
     
     
         6 . The cartridge case according to  claim 5  wherein the tubular sidewall is made from aluminum or an aluminum alloy. 
     
     
         7 . The cartridge case according to  claim 3  wherein the tubular sidewall is widest at the junction between the front face of the circumferential groove and the wall of the cup-shaped portion, tapering toward its forward end and toward its rearward end. 
     
     
         8 . The cartridge case according to  claim 1  further comprising a bonding agent between the generally tubular sidewall and the heel portion. 
     
     
         9 . The cartridge case according to  claim 1  wherein the circumferential groove has a bottom face, facing generally radially outwardly, disposed between the forward face and the rearward face, and wherein the rearward end portion of the tubular sidewall extends over the sloped forward face and at least part of the bottom face. 
     
     
         10 . A cartridge case comprising:
 a heel element, made of a first material, having a forward portion, a generally flat rear end portion, and a circumferential groove, having a generally radially extending rear face and a sloped forward face;   a separate generally tubular sidewall, made of a second material, different from the first material, the rearward end portion of the sidewall extending over the forward portion of the heel element and over the sloped forward face into the circumferential groove.   
     
     
         11 . The cartridge case according to  claim 10  wherein the forward portion of the heel element is generally cup-shaped, comprising a wall that tapers toward its forward end. 
     
     
         12 . The cartridge case according to  claim 12  wherein the circumference of the wall tapers toward the forward end of the heel element. 
     
     
         13 . The cartridge case according to  claim 13  wherein the heel portion is made from stainless steel. 
     
     
         14 . The cartridge case according to  claim 14  wherein the tubular sidewall is made from aluminum or an aluminum alloy. 
     
     
         15 . The cartridge case according to  claim 13  wherein the tubular sidewall is widest at the junction between the front face of the circumferential groove and the wall of the cup-shaped portion, tapering toward its forward end and toward its rearward end. 
     
     
         16 . The cartridge case according to  claim 10  wherein the circumferential groove has a bottom face, facing generally radially outwardly, disposed between the forward face and the rearward face, and wherein the rearward end portion of the tubular sidewall extends over the over the sloped forward face and at least part of the bottom face. 
     
     
         17 . The cartridge case according to  claim 17  further comprising a bonding agent between the generally tubular sidewall and the heel portion.