The self-propelled gun GMC M12 had been used through the Second World War by the U.S. Army. It absolutely was developed on hull regarding the M3 Lee / Grant tank on which ended up being set up the initial French GPF 155 mm weapon. The main armament, the ammunitions additionally the gun crew had been positioned in an open topped area behind the vehicle. Just the motorist's and also the radio operator’s seats had been protected. To absorb the results for the recoil while using the artillery piece, the M-12 was designed with a rear blade that was lowered and fixed in to the ground.