Firearm projectile with bonded rear core

Abstract

The present invention is a controlled expansion projectile ( 20 ) having a bonded rear core and includes a metal jacket ( 22 ), a dense core ( 24 ), and a tip ( 26 ). Metal jacket ( 22 ) includes a nose portion ( 28 ), a middle portion ( 30 ), and a heel portion ( 32 ). Nose portion ( 28 ) includes a front cavity ( 34 ) and heel portion ( 32 ) includes a rear cavity ( 36 ) defined by sidewalls ( 40 ), an open end ( 42 ), and heel ( 44 ). Dense core ( 24 ) is typically formed from lead but may be formed from lead compounds or other heavy metals. Dense core ( 24 ) may be enclosed in rear cavity ( 36 ) using a closure disc ( 48 ) joined with heel ( 44 ) to seal open end ( 42 ). Dense core ( 24 ) is joined with sidewalls ( 40 ) thereby forming a bond ( 52 ). Bond ( 52 ) may be a metallurgical bond ( 54 ), a mechanical bond ( 56 ), or an adhesive bond ( 58 ). Tip ( 26 ) is at least partially inserted in front cavity ( 34 ). Sidewalls ( 40 ) of rear cavity ( 36 ) are softened during either a metallurgical bonding process or other processes.

1 . A controlled expansion projectile, comprising: 
 a unitary metal jacket including nose, middle, and heel portions, said nose portion including a front cavity and said heel portion including rear cavity having sidewalls, said nose and heel portions joined to one another via said middle portion;    a dense core contained within said rear cavity and bonded to said sidewalls; and    a tip at least partially inserted in said front cavity.    
   
   
       2 . A projectile according to  claim 1 , further comprising a metallurgical bond between said sidewalls and said dense core.  
   
   
       3 . A projectile according to  claim 1 , further comprising a mechanical bond between said sidewalls and said dense core.  
   
   
       4 . A projectile according to  claim 1 , further comprising an adhesive bond between said sidewalls and said dense core.  
   
   
       5 . A projectile according to  claim 1 , wherein said dense core includes lead.  
   
   
       6 . A projectile according to  claim 1 , wherein said front cavity does not contain lead.  
   
   
       7 . A projectile according to  claim 1 , wherein said tip includes a substantially polycarbonate or polypropylene material.  
   
   
       8 . A projectile according to  claim 1 , further comprising a closure disc joined with said heel portion to enclose said dense core within said front cavity.  
   
   
       9 . A projectile according to  claim 1 , wherein said metal jacket has a substantially H-shaped axial cross section.  
   
   
       10 . A projectile according to  claim 1 , further comprising means for joining said dense core with said sidewalls.  
   
   
       11 . A projectile according to  claim 10 , wherein said means for joining prevents said dense core from separating from said metal jacket.  
   
   
       12 . A projectile according to  claim 10 , wherein said means for joining includes means for softening said metal jacket adjacent said rear cavity.  
   
   
       13 . A projectile according to  claim 1 , further comprising means for preventing said dense core from separating from said metal jacket when the projectile strikes an object.  
   
   
       14 . A projectile according to  claim 1 , further comprising means for enclosing said dense core within said front cavity.  
   
   
       15 . A projectile according to  claim 1 , further comprising means for increasing a ballistic coefficient of the projectile.  
   
   
       16 . A projectile according to  claim 1 , wherein said metal jacket is softened adjacent said rear cavity.  
   
   
       17 . A projectile according to  claim 1 , further comprising means for softening said metal jacket adjacent said rear cavity.  
   
   
       18 . A projectile according to  claim 1 , wherein upon striking an object after being fired, said front cavity peels back toward said heel portion thereby forming petals and said sidewalls and said dense core accordion forward toward said nose portion thereby defining a bulge.  
   
   
       19 . A projectile according to  claim 18 , further comprising means for supporting said petals.  
   
   
       20 . A projectile according to  claim 19 , wherein said means for supporting is said bulge.  
   
   
       21 . A method of fabricating a controlled expansion projectile, comprising the steps of: 
 providing a unitary metal jacket including nose, middle, and heel portions, said nose portion including a front cavity and said heel portion including rear cavity having sidewalls, said nose and heel portions joined to one another via said middle portion;    filling said rear cavity with a dense core;    bonding said dense core to said sidewalls of said rear cavity;    softening said metal jacket adjacent said rear cavity; and    inserting a tip in said front cavity.    
   
   
       22 . A method according to  claim 21 , wherein said bonding step includes forming a metallurgical bond between said sidewalls and said dense core.  
   
   
       23 . A method according to  claim 21 , wherein said bonding step includes forming a mechanical bond between said sidewalls and said dense core.  
   
   
       24 . A method according to  claim 21 , wherein said bonding step includes forming an adhesive bond between said sidewalls and said dense core.  
   
   
       25 . A method according to  claim 21 , further comprising the step of enclosing said dense core within said front cavity.  
   
   
       26 . A controlled expansion projectile, comprising: 
 a unitary metal jacket including nose, middle, and heel portions, said nose portion including a front cavity and said heel portion including rear cavity having sidewalls, said nose and heel portions joined to one another via said middle portion;    a dense core contained within said rear cavity;    means for bonding said dense core to said sidewalls; and    means for increasing a ballistic coefficient of the projectile.    
   
   
       27 . A projectile according to  claim 26 , wherein said means for bonding includes a metallurgical bond between said sidewalls and said dense core.  
   
   
       28 . A projectile according to  claim 26 , wherein said means for bonding includes a mechanical bond between said sidewalls and said dense core.  
   
   
       29 . A projectile according to  claim 26 , wherein said means for bonding includes an adhesive bond between said sidewalls and said dense core.  
   
   
       30 . A projectile according to  claim 26 , wherein said means for increasing a ballistic coefficient of the projectile includes a tip at least partially inserted in said front cavity.