http://kwk.us/recoil.html has a calculator that outputs recoil momentum, velocity, and energy. It give a discourse on the formulas used, including the effect of the escaping gas velocity, and how to estimate gas velocity. You can choose which gas velocity to input either directly or as a factor that multiplies the charge weight.

Peak recoil acceleration is discussed and dismissed as happening within a few hundredths of an inch movement. Example, a .308 Win and .300 Wby have about the same peak acceleration, but much different recoil overall.

Recoil sharpness due to the gun reaching full speed in less time is considered, but does not seem to be the answer.

A method developed by John Barsness is also considered.

Rifle recoil is the main subject at this site.

A shotgun site with formulas is http://zknives.com/bali/brcstgn.shtml . Takes a little work to understand the math. I see this site uses 1.5 times the muzzle velocity for charge velocity.

Last edited by J. Hall; 04/20/10 01:22 PM.