@2avenous: A Russian mobile air defense team training with a YakB-12.7 machine gun ended in chaos when the gunner almost killed his own instructor. The reason is surprisingly simple. Someone thought it was a good idea to mount the YakB-12.7 — a machine gun producing roughly 1,400 kgf (about 1.4 tonnes) of recoil force — on a rotating turret where the barrel’s axis is offset from the turret’s axis of rotation. The YakB-12.7 is the primary weapon of the USPU-24 used on the Mi-24 attack helicopter.