Hollow core projectile

Abstract

The invention herein describes an aerodynamically improved projectile which has less overall mass and achieves higher maximum velocities. The projectile has a jacket with a nose opening and a base opening and a core disposed therein. The core is open-ended and has a channel defined from the open forward end to the open base end. The channel is axially aligned with the nose opening and base opening of the jacket. Removably attached to the base opening is a base cover that is engineered to detach from the projectile during flight. A pressure differential created in the channel during projectile flight causes the base cover to detach from the projectile, thereby fully opening the channel.

What is claimed is: 
     
         1 . A projectile for an ammunition cartridge, the projectile comprising:
 an open-ended hollow core having a channel defined from an open forward end to an open base end;   a jacket covering the core, the jacket having a nose opening and a base opening that are axially aligned with the channel; and   a base cover having means for removably attaching to projectile at the base opening.   
     
     
         2 . The projectile of  claim 1 , wherein the base cover further comprises a shaft extending into the channel. 
     
     
         3 . The projectile of  claim 2 , wherein the shaft is tapered. 
     
     
         4 . The projectile of  claim 2 , wherein the removable attachment means comprises a frictional engagement between the shaft and the channel. 
     
     
         5 . The projectile of  claim 1 , wherein the removable attachment means is configured to cause the base cover to detach during flight of the projectile. 
     
     
         6 . The projectile of  claim 5 , wherein the base cover detaches during flight under force from air pressure in the channel. 
     
     
         7 . The projectile of  claim 1 , wherein the base cover completely blocks the base opening. 
     
     
         8 . The projectile of  claim 1 , wherein a forward end of the projectile tapers inwardly toward a longitudinal centerline of the projectile forming an ogive. 
     
     
         9 . The projectile of  claim 8 , wherein the nose opening and the base opening are concentrically aligned with the channel about the longitudinal centerline. 
     
     
         10 . The projectile of  claim 1 , comprising a boat tail. 
     
     
         11 . The projectile of  claim 1 , wherein the channel is substantially cylindrical. 
     
     
         12 . The projectile of  claim 1 , wherein the jacket is made from polymer material. 
     
     
         13 . A jacketed bullet comprising:
 a core having a hollow channel extending from a nose aperture to a base aperture;   a polymer jacket substantially enclosing the core, the polymer jacket having a nose opening aligned with the nose aperture and a base opening aligned with the base aperture.   
     
     
         14 . The jacketed bullet of  claim 13 , further comprising a cover removably attached to the base opening. 
     
     
         15 . A method for manufacturing a hollow core projectile, the method comprising the steps of:
 forming a jacket having a nose opening and a base opening;   forming a core;   disposing the core in the jacket; and   boring a channel in the core from the nose opening to the base opening to form an open-ended core.   
     
     
         16 . The method of  claim 15 , further comprising the step of removably attaching a cover to the base opening. 
     
     
         17 . The method of  claim 16 , wherein the step of removably attaching the cover to the base opening comprises inserting a tapered shaft, integrally connected to the cover, through the base opening and into the channel. 
     
     
         18 . The method of  claim 15 , wherein the step of forming the jacket further comprises forming a boat tail at a base end. 
     
     
         19 . The method of  claim 15 , wherein the step of forming the core further comprises tapering a forward end inwardly toward a longitudinal centerline of the core to form an ogive. 
     
     
         20 . The method of  claim 19 , further comprising the step of tapering a nose end of the jacket inwardly to substantially match the inward taper of the forward end of the core to define a projectile ogive.