Rifling Twist Calculator
This calculator operates by the Greenhill
Formula. The Formula for this calculator is setup for Copper
Jacketed Lead Core Bullets Only.
Note 1: Velocity Value- Enter the following value which corresponds
to the bullet's muzzle velocity.
Velocity
Value
up to 1000fps
48
1000-1499fps
125
1500-2999fps
150
3000-4500fps
180