The Maths as promised: Time of fall (Box is actually 23inches above snow level): 2ft = 1/2(32)t^2 2/16 = t^2 t = .35s Distance traveled: 253 strides x 2.5ft/stride = 633ft Speed: v = d/t v = 633/.35 v = about 1800fps this seems really fast so as a check I looked at the video to find how fast the gun recoiled (good thing I didn't put a rock behind it) I know the mass of the 2 objects and I know that the momentum should be the same assuming no losses. the gun weighs 3.7kg and the ball weighs .0