Here is a good site to confirm the premise of this post .....
I used it when determining powders for my 505 Gibbs
shooterscalculator.com
I used it when determining powders for my 505 Gibbs
ShootersCalculator.com | Recoil Calculator
An online calculator that calculates the recoil energy, impulse, and velocity of a firearm according to the firearm's weight, powder charge, bullet weight, and bullet muzzle velocity.