Crimped-case cartridge

Abstract

A crimped-case cartridge comprising a bullet and a casing wherein the casing has alternating crimped and uncrimped sections at its terminal end. The crimped sections form increased contact sections with the bullet, with the uncrimped sections maintaining proper head space for the cartridge. The amount of crimped section versus the amount of uncrimped section is variable to meet a variety of desired ballistic characteristics. Likewise, the amount of taper, angle of crimp, depth of crimp, and pressure applied in the crimped section is also variable. The crimped-case cartridge is employable with bullets having cannelure depressions of any geometry or no cannelure at all. Additionally, a bullet having a cannelure geometry mated to the crimped section geometry is disclosed. Likewise, a plurality of taper-crimp dies forming the crimped-die cartridge is disclosed.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A crimped casing cartridge, comprising: 
 a bullet; and    a casing having an open end, wherein the casing is attached to the bullet at the open end via a plurality of crimped sections, leaving a plurality of uncrimped sections at the open end.    
     
     
         2 . The crimped cartridge of  claim 1 , wherein the bullet has at least one of a crimp-mated cannelure, a standard geometry cannelure, or no cannelure.  
     
     
         3 . The crimped cartridge of  claim 1 , wherein at least one of the crimped sections is crimped against the bullet.  
     
     
         4 . The crimped cartridge of  claim 1 , wherein at least one of the uncrimped sections of the casing maintains the proper cartridge head space.  
     
     
         5 . The crimped cartridge of  claim 1 , wherein two uncrimped sections are created.  
     
     
         6 . The crimped cartridge of  claim 1 , wherein the crimped sections and uncrimped sections alternate around the open end of the casing.  
     
     
         7 . The crimped cartridge of  claim 1 , wherein the total crimped section exceeds the total uncrimped section.  
     
     
         8 . The crimped cartridge of  claim 1 , wherein the number of crimped sections is greater than the number of uncrimped sections.  
     
     
         9 . A method of forming a crimped-case cartridge, comprising: 
 providing a casing taper to remove any casing belling; and,    providing a crimping taper to the casing to form a plurality of alternating crimped and uncrimped sections at an end of the casing.    
     
     
         10 . The method of  claim 9 , wherein the casing taper returns the casing to a minimum chamber diameter.  
     
     
         11 . The method of  claim 9 , wherein at least two uncrimped sections are formed at the end of the casing.  
     
     
         12 . A bullet having a cannelure, the cannelure comprising: 
 a seating edge; and,    a tapered relief surface.    
     
     
         13 . The bullet of  claim 12 , wherein a cannelure is mated to receive a crimped section of a casing.  
     
     
         14 . The bullet of  claim 12 , further comprising a lubricant applied to an outer surface of the bullet.  
     
     
         15 . The bullet of  claim 12 , wherein the seating edge prevents bullet displacement in a casing prior to an ignition.  
     
     
         16 . A crimp-taper die, comprising: 
 a casing taper;    a crimp taper; and    at least one relief section within the crimp taper, wherein the at least one relief sections excludes a casing section within the relieved section from the crimp taper.    
     
     
         17 . The crimp-taper die of  claim 16 , wherein relief sections are formed in the casing taper.  
     
     
         18 . The crimp-taper die of  claim 16 , wherein relief sections are not formed in the casing taper.  
     
     
         19 . The crimp-taper die of  claim 16 , wherein at least two relief sections are formed in the crimp taper.  
     
     
         20 . The crimp-taper die of  claim 16 , wherein when a bullet and casing are inserted into the die, the spacing of the relief sections leave uncrimped sections around a perimeter of the casing adjacent the bullet to maintain a proper cartridge head spacing.  
     
     
         21 . A cartridge comprising: 
 a bullet;    a casing adjacent to the bullet; and    a means for crimping the casing to the bullet to ensure proper head space.    
     
     
         22 . The cartridge of  claim 21 , further comprising at least one uncrimped section at an end of the casing.