Handgun cartridge with shear groove bullet

Abstract

A rimless cartridge comprising a case and a bullet mounted therein. In embodiments, the bullet comprises a jacket having a cylindrical body portion, an ogive portion, and a plurality of longitudinally extending paths of weakness formed in the ogive portion and defining petals there between and extending rearward from the mouth. The bullet includes a malleable core mounted within the jacket. The bullet further comprises a circumferential groove between forward and rearward circumferential indentations imparted in the body portion of the jacket.

1 - 78 . (canceled) 
     
     
         79 . A rimless cartridge for firing in a handgun, comprising:
 a case having a forward cylindrical wall connecting to a rearward head, the forward cylindrical wall defining an interior cavity and terminating at a leading edge defining a bullet opening;   propellant in the interior cavity; and   a bullet inserted into the bullet opening, the bullet comprising a core and a jacket at least partially enveloping the core, the bullet having a rearward cylindrical body portion and a forward tapered portion, wherein the bullet includes a circumferential groove positioned between a rearward circumferential indentation formed in the rearward cylindrical body portion and a forward circumferential indentation formed in the forward tapered portion, wherein the circumferential groove is configured to release expansion petals upon over-expansion of the bullet after impact with a hard surface.   
     
     
         80 . The rimless cartridge of  claim 79 , wherein the forward tapered portion includes a plurality of axially oriented skives defining expansion petals in the jacket. 
     
     
         81 . The rimless cartridge of  claim 80 , wherein the forward circumferential indentation is axially positioned at or adjacent to a rearward end of at least one of the plurality of skives. 
     
     
         82 . The rimless cartridge of  claim 81 , wherein the circumferential groove extends into the jacket, forming an outwardly opening acute angle. 
     
     
         83 . The rimless cartridge of  claim 82 , wherein the acute angle is about 60 degrees. 
     
     
         84 . The rimless cartridge of  claim 83 , wherein the circumferential groove has a bottom flat at an innermost portion of the circumferential groove. 
     
     
         85 . The rimless cartridge of  claim 84 , wherein the forward circumferential indentation defines a first diameter of the bullet and the circumferential groove defines a second diameter, the first and second diameters being substantially equal. 
     
     
         86 . A bullet for a rimless cartridge, comprising:
 a core;   a jacket at least partially enveloping the core, the jacket having a rearward cylindrical body portion and a forward tapered portion;   a plurality of longitudinally extending paths of weakness formed in the forward tapered portion, defining expansion petals;   a rearward circumferential indentation formed in the rearward cylindrical body portion;   a forward circumferential indentation formed in the forward tapered portion; and   a circumferential groove positioned between the rearward circumferential indentation and the forward circumferential indentation, wherein the circumferential groove is configured to allow controlled separation of the expansion petals upon impact with a hard surface.   
     
     
         87 . The bullet of  claim 86 , wherein the circumferential groove extends into the jacket, forming an outwardly opening acute angle. 
     
     
         88 . The bullet of  claim 87 , wherein the acute angle is about 60 degrees. 
     
     
         89 . The bullet of  claim 88 , wherein the circumferential groove has a bottom flat at an innermost portion of the circumferential groove. 
     
     
         90 . The bullet of  claim 89 , wherein the forward circumferential indentation defines a first diameter of the bullet and the circumferential groove defines a second diameter, the first and second diameters being substantially equal. 
     
     
         91 . The bullet of  claim 90 , wherein the rearward circumferential indentation comprises a knurled surface. 
     
     
         92 . The bullet of  claim 91 , wherein the core comprises a malleable metal and the jacket comprises a metallic material having a higher tensile strength than the core. 
     
     
         93 . A method of making a bullet for a rimless cartridge, comprising:
 forming a cup-shaped jacket blank;   forming a malleable core within the jacket blank;   providing a plurality of axially oriented paths of weakness in a forward portion of the jacket blank;   forming a cavity in a forward end of the malleable core;   deforming the forward end of the jacket blank to form a tapered portion;   imparting a rearward circumferential indentation into a rearward cylindrical body portion of the jacket blank;   imparting a forward circumferential indentation into the tapered portion of the jacket blank; and   imparting a circumferential groove between the rearward circumferential indentation and the forward circumferential indentation, wherein the circumferential groove is configured to allow controlled separation of expansion petals formed by the paths of weakness upon impact with a hard surface.   
     
     
         94 . The method of  claim 93 , wherein the circumferential groove extends into the jacket, forming an outwardly opening acute angle. 
     
     
         95 . The method of  claim 94 , wherein the acute angle is about 60 degrees. 
     
     
         96 . The method of  claim 95 , wherein the circumferential groove has a bottom flat at an innermost portion of the circumferential groove. 
     
     
         97 . The method of  claim 96 , wherein the forward circumferential indentation defines a first diameter of the bullet and the circumferential groove defines a second diameter, the first and second diameters being substantially equal. 
     
     
         98 . The method of  claim 97 , further comprising imparting a knurled surface on the rearward circumferential indentation to enhance retention of the jacket to the core.