Bullet with booster filling and its manufacture

Abstract

A bullet having a cavity in its forward end that is open at that end and a filling situated within said cavity. Preferably, the filling comprises an elastomer. Preferably, the elastomer filling is vulcanized. More preferably, the vulcanized elastomer filling has a Shore hardness in the range from about 6 to about 90. Alternatively, the filling is a colored rigid polymer filling, if a non-expanding training hollow point bullet is desired. In particular, the invention is a filling and its application to hollow point bullets for the purposes of: improving bullet expansion during the penetration of liquid targets; preventing clogging with debris from intermediate targets; increasing expansion during the perforation of hard materials; preventing the expansion of training bullets; and allowing users to identify different cartridge designs. The invention is also devices and methods for introducing the filling into the cavity.

1 . A bullet comprising: 
 a metal bullet body having a body diameter and a cavity in its forward end that is open at that end, said cavity having a bottom; and    an elastomer filling situated substantially within said cavity;    wherein said metal bullet body is operative to expand when the bullet strikes a target.    
   
   
       2 . The bullet of  claim 1  wherein the elastomer filling has a cylindrical shape having an elastomer filling diameter.  
   
   
       3 . The bullet of  claim 1  wherein the elastomer filling has Shore hardness in the range from about 30 to about 90.  
   
   
       4 . The bullet of  claim 2  wherein the elastomer filling diameter is less than half of the body diameter.  
   
   
       5 . The bullet of  claim 4  wherein the elastomer filling has at least one axial groove.  
   
   
       6 . The bullet of  claim 1  wherein the elastomer filling has a transverse cross-sectional shape that is polygonal.  
   
   
       7 . The bullet of  claim 1  wherein the elastomer is colored.  
   
   
       8 . The bullet of  claim 1  wherein the bottom of the cavity is rounded or non-planar.  
   
   
       9 . The bullet of  claim 1  wherein the bottom of the cavity is square or flat.  
   
   
       10 . The bullet of  claim 1  wherein the cavity has at least one axial groove.  
   
   
       11 . The bullet of  claim 1  wherein the elastomer filling is a plug having at least one axial element selected from the group consisting of an axial groove and an axial holes.  
   
   
       12 . The bullet of  claim 1  wherein the elastomer filling is formed into a cylindrical insert before it is inserted in the cavity.  
   
   
       13 . The bullet of  claim 12  wherein the insert is exposed to lubricant that can be absorbed by the filling after it is forced into the cavity.  
   
   
       14 . The bullet of  claim 1  wherein the elastomer filling is a vulcanizible elastomer that is poured into the cavity before it is vulcanized.  
   
   
       15 . The bullet of  claim 1  wherein the elastomer filling comprises a thermoplastic that is injected into the cavity.  
   
   
       16 . The bullet of  claim 1  wherein the elastomer filling is operative to transmit stagnation pressure to the walls of the cavity when the bullet strikes a liquid target.  
   
   
       17 . The bullet of  claim 1  wherein the elastomer filling is operative to flatten and convert axial forces into radial forces that contribute to bullet expansion when the bullet strikes a hard target.  
   
   
       18 . The bullet of  claim 1  further comprising cladding surrounding said body wherein said cladding and said body have a plurality of axial stress raisers formed therein adjacent to said forward end.  
   
   
       19 . The bullet of  claim 1  wherein said forward end is swaged to compress said elastomer filling in said cavity.  
   
   
       20 . The bullet of  claim 1  wherein said body has an annular stress raiser formed therein adjacent to the bottom of said cavity.  
   
   
       21 . A projectile comprising: a metal bullet body having a cavity in its forward end that is open at that end and an elastomer filling situated within said cavity, wherein the characteristics of the bullet are indicated by the color of the elastomer filling, said color being visible at the forward end of the bullet.  
   
   
       22 . A training bullet comprising: 
 a bullet body having a cavity in its forward end that is open at that end and an rigid polymer filling situated within said cavity;    wherein said filling is operative to cause the bullet to have the same ballistic features as a bullet having an elastomer filling of approximately the same size and is operative to prevent the bullet from expanding during penetration of a liquid target.    
   
   
       23 . The training bullet of  claim 22  wherein the rigid polymer filling is colored.  
   
   
       24 . The training bullet of  claim 22  wherein the rigid polymer filling is a plug having at least one axial groove or axial hole.  
   
   
       25 . The training bullet of  claim 22  wherein the rigid polymer filling has the same density as the elastomer filling that is used in the non-training version of the bullet.  
   
   
       26 . A bullet comprising: 
 a body having a cavity in its forward, nose end that is open at that end; and    a plug compressed within said cavity by swaging or crimping said nose.    
   
   
       27 . The bullet of  claim 26  wherein the plug has a loose fit in the cavity prior to being compressed in the cavity by swaging or crimping.  
   
   
       28 . A cartridge comprising: 
 a cartridge case containing the bullet of  claim 1 , a powder charge or load and a primer.    
   
   
       29 . A bullet comprising: 
 a projectile having a metal body having a hollow point that is filled with an elastomer, said projectile having an unjacketed, flat nose.    
   
   
       30 . A bullet comprising: 
 a generally cylindrical, metal body portion having a longitudinal axis and a first axial cavity portion disposed along the longitudinal axis;    a metal nose portion disposed forwardly of said body portion, said nose portion having an unjacketed forward end and a second axial cavity portion disposed along the longitudinal axis; and    a generally cylindrical elastomer filling situated within the axial cavity portions, said elastomer filling having a generally flat or convex forward end.    
   
   
       31 . A bullet comprising: 
 a metal body having a substantially cylindrical portion and a frontal portion having a first longitudinal cavity part; and    an elastomer portion, at least a first part of which is disposed in the first cavity part, the elastomer portion having a substantially flat, unjacketed forward end.    
   
   
       32 . The bullet of  claim 31  wherein the cylindrical portion and the frontal portion are also unjacketed.  
   
   
       33 . The bullet of  claim 31  wherein the generally cylindrical portion has a second longitudinal cavity part in which a second part of the elastomer portion is also disposed.  
   
   
       34 . The bullet of  claim 31  wherein the tip of the frontal portion has a smaller diameter than the diameter of the cylindrical portion.  
   
   
       35 . An adequate penetration, optimum expansion bullet for use against barriers of soft to medium-hardness comprising: 
 a jacket formed of a malleable metal and having a generally cylindrical sidewall, a nose portion disposed forwardly of said cylindrical sidewall, an open forward end, and a rear end portion, said nose portion having a nose-defining wall extending between said cylindrical wall and said open forward end;    an elastomer core disposed in part at least within said nose-defining wall; and    a metal core seated behind said elastomer core and within said generally cylindrical sidewall in close-fitting relation and extending rearwardly to a position adjacent said rear end portion of said generally cylindrical jacket sidewall.    
   
   
       36 . A projectile comprising: 
 a metal body having a generally cylindrical portion and a frontal portion, both the cylindrical portion and the frontal portion having a longitudinal cavity having walls; and    an elastomer portion that is disposed in the cavity, the elastomer portion having a generally flat, unjacketed forward end and being operative to transmit a stagnation pressure that is exerted upon the forward end when the projectile strikes a barriers to the walls of the cavity.    
   
   
       37 . A bullet comprising: 
 a metal body having an open cavity in its forward end, the cavity having walls; and    means for transmitting a stagnation pressure to the walls of the cavity when said stagnation pressure is exerted upon the forward end when the bullet strikes a liquid target.    
   
   
       38 . A process for making an improved bullet comprising: 
 filling a cavity in a bullet having a flat front end with an elastomer plug, the plug having approximately the same dimensions as the cavity and a flat forward end that ends in the approximately same plane as the front end.    
   
   
       39 . The process of  claim 38  wherein the filling step involves placing a thermoplastic elastomer plug into a hollow point bullet.  
   
   
       40 . A process for making an improved bullet comprising: 
 filling a cavity in a bullet having a nose with a plug; and    swaging or crimping the nose.    
   
   
       41 . The process of  claim 40  wherein the plug has a loose fit with the cavity prior to the swaging or crimping step.  
   
   
       42 . An apparatus comprising: 
 means for performing the filling step of  claim 40;  and    means for performing the swaging or crimping step of  claim 40 .    
   
   
       43 . An apparatus for inserting an elastomer into a cavity in a bullet comprising: 
 a table for supporting the bullet;    a rotary plate having a plurality of holes along its periphery that are operative to accept a segment of cord, said plate being rotatably connected to the table and being capable of shearing off said segment of cord during its rotation;    an elastomer cord feeding device having a cord feeding device bushing that situated adjacent to the rotary plate and through which the cord feeding device is capable of feeding cord into each hole in the rotary table; and    a punch having a punch bushing that situated adjacent to the rotary plate and through which the punch is operative to push the sheared segment of cord into the cavity in the bullet.    
   
   
       44 . A process of using the apparatus of  claim 43  to produce a bullet comprising an elastomer filled cavity having an open forward end comprising: 
 a step for introducing an elastomer cord to the apparatus of  claim 43;  and    a step for shearing the elastomer cord to produce a plug; and    a step for inserting the plug into a cavity of a hollow point bullet.    
   
   
       45 . A bullet comprising an elastomer filled cavity having an open forward end that is produced by the process of  claim 44 .  
   
   
       46 . An apparatus for inserting an elastomer into a cavity in a bullet comprising: 
 a table for supporting the bullet;    a reciprocating feeder having a hole in one end that is operative to accept a segment of cord, said feeder being slidably connected to the table and being capable of shearing off said segment of cord during its backward movement; and    an elastomer cord feeding device having a cord feeding device bushing that situated adjacent to the reciprocating feeder and through which the cord feeding device is capable of feeding cord into the hole in the reciprocating feeder and pushing the sheared segment of cord into the cavity in the bullet when the feeder is in the forward position.    
   
   
       47 . A process of using the apparatus of  claim 46  to produce a bullet comprising an elastomer filled cavity having an open forward end comprising: 
 a step for introducing an elastomer cord to the apparatus of  claim 43;  and    a step for shearing the elastomer cord to produce a plug; and    a step for inserting the plug into a cavity of a hollow point bullet.    
   
   
       48 . A bullet comprising an elastomer filled cavity having an open forward end that is produced by the process of  claim 47.