Patent ID: 7802394

Claim:
In combination: a cartridge having a bullet; the bullet having a diameter, a length, a ballistic coefficient (BC), and a muzzle velocity (V 1 ) greater than 1250 ft/sec; and a rifle including: a barrel for receiving said bullet including: rifling having a twist substantially equal to: 83.7 ÷ ( bullet ⁢ ⁢ ⁢ length × 2 ⁢ B ⁢ ⁢ C bullet ⁢ ⁢ diameter ) × bullet ⁢ ⁢ diameter × [ 1 + ( V 3 V 1 × 0.667 ) ] where: V 2 , a transonic reference speed, is 1,250 ft/sec., and V 3 is V 1 minus V 2 .