Dual core ammunition

Abstract

A jacket precursor, a pellet first core precursor, and a second core precursor are provided. The pellet and second core precursor are inserted into the jacket precursor. The second core precursor is pressed against the pellet so as to deform the pellet to fill a frontal volume of the jacket precursor as a first core with relatively less (if any) deformation of the second core precursor. An aft portion of the jacket precursor is deformed to contain the second core precursor as a second core. Preferred embodiments are formed substantially as drop-in replacements for existing bullets. A match embodiment features a lead rear core and a very light front core (e.g., a carbonate powder). A non-toxic embodiment comprises a tin front core and a harder rear core.

What is claimed is  
     
         1 . A method for manufacturing a bullet comprising: 
 providing a jacket precursor;    providing a pellet first core precursor;    inserting the pellet into the jacket precursor;    providing a second core precursor;    inserting the second core precursor into the jacket precursor aft of the pellet;    pressing the second core precursor against the pellet so as to deform the pellet to fill a frontal volume of the jacket precursor as a first core, with relatively less deformation of the second core precursor; and    deforming an aft portion of the jacket precursor to contain the second core precursor as a second core.    
     
     
         2 . The method of  claim 1  wherein: 
 a forward half of the jacket precursor is already in a substantially final shape prior to insertion of the pellet.  
 
     
     
         3 . The method of  claim 1  wherein: 
 said pressing comprises at least two stages, a first relatively low force/pressure stage deforming the pellet to substantially fill said frontal volume and a second relatively high force/pressure stage deforming the second core precursor to laterally expand to fill an aft volume of the jacket precursor.  
 
     
     
         4 . The method of  claim 1  wherein: 
 the second core precursor is provided having a convex front surface and a lateral surface which is cylindrical along a majority of a length of the second core precursor.  
 
     
     
         5 . The method of  claim 1  wherein: 
 the second core precursor is provided having essentially a convex front surface, a cylindrical lateral surface, and a convex rear surface.  
 
     
     
         6 . The method of  claim 1  wherein: 
 the pellet has a density less than 30% of a density of the second core.  
 
     
     
         7 . The method of  claim 1  wherein the pellet is provided as a sphere.  
     
     
         8 . The method of  claim 7  wherein the second core precursor is provided as a circular cylinder.  
     
     
         9 . The method of  claim 1  wherein the first and second cores abut.  
     
     
         10 . The method of  claim 1  wherein the first core is essentially pure tin having a tin content of at least 99.85%, by weight, a yield strength of 11.0 MPa or less and a hardness of from about 3 to about 5 HB.  
     
     
         11 . The method of  claim 10  wherein the second core is essentially pure copper.  
     
     
         12 . The method of  claim 10  wherein the second core is essentially a polymer filled with a tungsten-based material.  
     
     
         13 . The method of  claim 1  wherein the first core is substantially a powder having a specific gravity less than 3.0.  
     
     
         14 . The method of  claim 13  wherein the second core is lead-based.  
     
     
         15 . The method of  claim 1  further comprising loading the bullet in a case selected from the group consisting of 0.357 Magnum 0.357 Sig, 0.38 Special, 0.40 Smith & Wesson, 9 mm Luger, and 10 mm Automatic to form a cartridge.  
     
     
         16 . The method of  claim 15  wherein the case is 9 mm Luger.  
     
     
         17 . The method of  claim 15  wherein the loading inserts the bullet into the case so that the cartridge has a length of 1.165-0.025 inch.  
     
     
         18 . The bullet of  claim 1  having a maximum diameter between 0.35 and 0.46 inch.  
     
     
         19 . A bullet comprising: 
 a jacket;    a first core contained within the jacket; and    a second core contained within the jacket aft of the first core;    wherein the second core is lead-based and the first core consists in major part of a non-metallic powder.    
     
     
         20 . The bullet of  claim 19  wherein: 
 the first core comprises at least 80.0 weight percent of one or more carbonates;  
 the second core comprises at least 95.0 weight percent lead; and  
 the jacket comprises at least 50.0 weight percent copper.  
 
     
     
         21 . The bullet of  claim 19  being an ogival bullet.  
     
     
         22 . The bullet of  claim 19  being full metal case, non-hollowpoint bullet.  
     
     
         23 . The bullet of  claim 19  wherein the bullet is of nominal 9 mm caliber and has a mass of 123.5-124.5 grains.  
     
     
         24 . A bullet comprising: 
 a jacket;    a first core contained within the jacket; and    a second core contained within the jacket aft of the first core, wherein: 
 the first core consists of at least 50 weight percent tin; and  
 the second core consists of at least 50 weight percent tungsten.  
   
     
     
         25 . The bullet of  claim 24  wherein: 
 the first core has deformability effective so that the bullet will not defeat level  2  body armor when impacted thereon.  
 
     
     
         26 . The bullet of  claim 24  wherein: 
 the first core comprises at least 80.0 weight percent tin;  
 the second core comprises at least 95.0 weight percent tungsten-filled polymer; and  
 the jacket comprises at least 50.0 weight percent copper.  
 
     
     
         27 . The bullet of  claim 24  wherein: 
 the bullet has a weight of 120-125 grains.