Wow, thanks for the full explanation. :D Also, very helpful calc MrCrowley So if i have a 2.6lb piston in a 4" chamber and 1.3" stroke at 1000psi, that would be: a = P*A/m, or 1000*12.56/2.6 = 4833 in/s^2 = 402ft/s^2 Then d=0.5at^2, or 1.3=0.5*402*t^2, so t=0.0804s Then Vf= a*t, so 32.33ft/s These l...