I can see from the formulae that a bullet will have greater KE than the gun even though the mometum of the kickback is equal to that of the bullet. I also know that a bullet will do a lot more damage to a wall than the backfire of the gun. Whats behind this? Is it simply the concentration of energy in such a small amount of particles that makes the bullet more destructive? Force takes mass into account though so I'm assuming the bullet cannot do more work than the backfiring gun.