Bullet Stabilization in Subsonic Flight

Abstract

The present invention relates to increasing the flight stability of a bullet in subsonic flight. The bullet may incorporate features that impart additional angular momentum during flight. Helical fins may be configured such that laminar airflow over the bullet during flight causes the bullet to rotate, increasing the angular momentum of the bullet and stabilizing it during flight. The fins may be self-forming during the use of the bullet or may be formed during manufacturing.

1 . A bullet comprising:
 a nose section;   a cylindrical midsection having a first diameter, wherein a surface of the cylindrical midsection is a first material having a first material hardness;   a cylindrical tail section having a second diameter, wherein the second diameter is greater than or equal to the first diameter, and wherein a surface of the cylindrical tail section is a second material having a second material hardness;   a concave base; and   wherein the second material hardness is less than or equal to the first material hardness, and wherein the second material hardness is such that the second material is capable of being mechanically formed into fins.   
     
     
         2 . The bullet of  claim 1 , wherein the first material is selected from the group consisting of copper and lead. 
     
     
         3 . The bullet of  claim 2 , wherein the second material is selected from the group consisting of aluminum and lead. 
     
     
         4 . The bullet of any  claim 3 , further comprising at least one core material. 
     
     
         5 . The bullet of  claim 4 , wherein the at least one core material is selected from the group consisting of tungsten, steel, copper, and lead. 
     
     
         6 . A bullet comprising:
 a parabolic nose;   a cylindrical midsection having a first radius;   a secant ogive tail;   at least one helical fin protruding from the secant ogive tail, wherein the at least one helical fin has a second radius less than or equal to the first radius, and wherein the at least one helical fin has a twist approximately equal to that of a standard barrel rifling.   
     
     
         7 . The bullet of  claim 6 , further comprising at least one jacket material. 
     
     
         8 . The bullet of  claim 7 , wherein the at least one jacket material is selected from the group consisting of copper and lead. 
     
     
         9 . The bullet of  claim 8 , further comprising at least one core material. 
     
     
         10 . The bullet of  claim 9 , wherein the at least one core material is selected from the group consisting of tungsten, steel, copper, and lead. 
     
     
         11 . A method of stabilizing a bullet in subsonic flight, the method comprising:
 firing a bullet comprising a nose section, a cylindrical midsection of a first material and a first diameter, and a cylindrical tail section of a second material and a second diameter;   forming fins in the cylindrical tail section of the bullet, wherein the fins are configured to impart angular momentum to the bullet via airflow over the fins during flight;   imparting angular momentum to the bullet via the airflow over the fins during flight.   
     
     
         12 . The method of  claim 11 , wherein the fins are formed by a rifling of a barrel through which the bullet is fired. 
     
     
         13 . The method of  claim 11 , wherein the fins are formed by at least one blade inside a casing in which the bullet is loaded. 
     
     
         14 . The method of  claim 11 , wherein the fins are formed during manufacturing of the bullet.