This isn't something that comes up often, but I figured since I've got one I might as well share it. At the link below is a recoil calculator that only needs 4 pieces of info. It will figure the recoil velocity and recoil force. I'll warn you now I've only tested this with medium caliber weapons. Nothing larger than a 20mm cannon in fact, and I know one of the calculations won't take anything over .50 caliber. I'll most likely be tinkering with it over the next few days to get it to work.
Recoil CalculatorI've got another version of this which spits our VERY accurate data for small arms. Anything up to and including a .50 BMG can be calculated, although I haven't tested it on something that size yet. It's up and running too if you want to eyeball it.
Small Arms calculatorThis thing will tell you muzzle energy, gun momentum, recoil force and recoil velocity. It only works on small arms, and NOT on large caliber weapons. Personally I use both calculators to figure things out, then average the two.
Just for fun here's the specs of the VYa-23 cannon.
Muzzle velocity: 2968 ft/sec
Muzzle energy: 58,410 ft-lbs
Shell weight: 6.8 oz
Recoil Velocity: 13.65 ft/sec
Recoil energy: 437.578 ft-lbs
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Flakbait [Delta6]
Delta 6's Flight SchoolPut the P-61B in Aces High"For yay did the sky darken, and split open and spew forth fire, and
through the smoke rode the Four Wurgers of the Apocalypse.
And on their canopies was tattooed the number of the Beast, and the
number was 190." Jedi, Verse Five, Capter Two, The Book of Dweeb 
[This message has been edited by flakbait (edited 02-24-2001).]
