Casing for soft projectile and method for making same

Abstract

A casing for a relatively soft projectile, such as a projectile for a paintball gun, has a concave portion for receiving a substantially round soft projectile, a driving band located behind the concave portion, and an aerodynamic portion located behind the driving band. The driving band preferably has lands and grooves for engaging rifling in the bore of the gun. The aerodynamic portion may have the approximate shape of a prolate spheroid or a paraboloid of revolution, or another shape that reduces eddy currents and drag behind the projectile. The concave portion of the casing preferably has an adhesive to prevent separation of the casing and projectile in flight. The casing may be solid or hollow; in the later case, it may be filled with a substance such as urethane foam.

1 . A casing for a soft projectile comprising:
 a concave portion for receiving a substantially round soft projectile;   a driving band located behind the concave portion; and,   an aerodynamic portion located behind the driving band.   
   
   
       2 . The casing of  claim 1 , where the driving band has lands and grooves for engaging rifling. 
   
   
       3 . The casing of  claim 1 , where the aerodynamic portion has approximately the shape of a section of a prolate spheroid. 
   
   
       4 . The casing of  claim 1 , where the aerodynamic portion has approximately the shape of a section of a paraboloid of revolution. 
   
   
       5 . The casing of  claim 1 , where the aerodynamic portion has approximately the shape of a cone. 
   
   
       6 . The casing of  claim 1 , where the aerodynamic portion has approximately the shape of a truncated cone. 
   
   
       7 . The casing of  claim 1 , where the casing has a hollow inside. 
   
   
       8 . The casing of  claim 1 , further comprising:
 a substance filling the inside of the casing.   
   
   
       9 . The casing of  claim 1 , further comprising:
 an adhesive located in the concave portion, for adhering the soft projectile to the casing.   
   
   
       10 . A casing for a soft projectile, comprising:
 a concave portion for receiving a substantially round soft projectile;   a driving band located behind the concave portion; and,   the casing having a flat surface immediately behind the driving band.   
   
   
       11 . The casing of  claim 10 , where the driving band has lands and grooves for engaging rifling. 
   
   
       12 . The casing of  claim 10 , where the casing has a hollow inside. 
   
   
       13 . The casing of  claim 10 , further comprising:
 a substance filling the inside of the casing.   
   
   
       14 . The casing of  claim 10 , further comprising:
 an adhesive located in the concave portion, for adhering the soft projectile to the casing.   
   
   
       15 . A casing for a soft projectile comprising:
 a concave portion for receiving a substantially round soft projectile;
 an adhesive located in the concave portion, for adhering the soft projectile to the casing; 
   a driving band located behind the concave portion;
 the driving band having lands and grooves for engaging rifling; 
   an aerodynamic portion located behind the driving band;
 the aerodynamic portion having approximately the shape of a section of a prolate spheroid; 
   the casing having a hollow inside; and,
 a substance filling the inside of the casing. 
   
   
   
       16 . A casing for a soft projectile comprising:
 a concave portion for receiving a substantially round soft projectile;
 an adhesive located in the concave portion, for adhering the soft projectile to the casing; 
   a driving band located behind the concave portion;
 the driving band having lands and grooves for engaging rifling; 
   an aerodynamic portion located behind the driving band;
 the aerodynamic portion having approximately the shape of a section of a prolate spheroid.