When they exit the jewelry store, J fires his Noisy Cricket at Edgar's stolen truck. The tiny gun is so powerful it knocks him back every time! In one part, he fires it and gets knocked back a few seconds AFTER firing.
Assuming that these guns are firing bursts of energy, as opposed to matter projectiles, then NONE of the guns (except Edgar's shotgun and pistol) should have recoil of any sort. Count the times that the "cool" guns are fired, note whether or not they seem to have recoil...there's a lot of bloopers in there. Even if the Noisy Cricket was firing projectiles, there is no possible way it could fire a projectile that needed enough force to generate that much recoil. Tanks don't have that much recoil.