this isn't a homework problem - and i am not a student! i have a 76mm tank gun (it's legal and registered w/ the feds in case you are wondering) and i am interested in firing blanks - but here is the problem: i want the gun to recoil like it does when firing live rounds. here is how the gun works: there is a long barrel (about 10' or so) and it is mounted on a set of shocks (like car shocks) that are on either side of it (see picture below.) ------ (oil/spring recoil piston) -------------------------------------- (barrel) ------ (oil/spring recoil piston) ^that is a picture of the gun and shocks. ok, so when a real round is fired out of it, the barrel pushes back ("recoil") and the shocks compress as the bullet comes out. in case anyone cares, the projectile is about 11 lbs or so and it is fired with about 3lbs of gun powder (actually, it's referred to as propellant, but it's technically just made of smokeless powder, just in a different format to make it burn slower.) so - back to the problem. if you don't have a bullet, but rather just an empty shell with gunpowder in it and you fire the gun, then all the 'energy' or force or whatever it's called just goes straight out of the barrel, and there is no recoil. when firing blanks, one typically uses about 1/2 lb of gun powder. my question is this: if i place a 'cap' over the front of the barrel with a very small hole in it, will this make it so a blank round will cause the gun to recoil on the shocks, or just create lots of pressure and blow out the cap? obviously i'd have to carefully experiment with the size of the hole in the cap - but principally, would this work? i'm not excited about experimenting with this thing without at least having some advisement on how it should theoretically operate under this 'blank' setup. it seems like anyone with a good grasp of elementary newtonian physics would be able to answer this (clearly, i don't.) note, i did initially post this in the homework section because i thought it was too elementary, and a nice person posted some guidance, but i'm looking for more detail. any insights would be appreciated.