I know the type. While in Saudi waiting for the ground war to start we were out in the middle of the desert with M110A2 (8") howitzers. Each howitzer section (4 sections in a platoon 2 platoons in a battery) pulled perimeter guard once every 4th night so that we had 2 up and guarding every night just in case some Iraqis crossed the border to start the ground war before we did.
One night, the gunner (a Sgt) for the 3rd section was starting to see things and loaded the M60 machine gun and then rammed an 8" howitzer round (208lb projectile) into the breech with a full charge of powder bags. Luckily, we did not have primers since we were not anywhere near the enemy at that time. So, they kept them locked up until the war started.
However, we did have M60 rounds, and he started firing it after trying to stuff a lit cigarette into the primer hole of the howitzer hoping to somehow ignite the charges. He had the tube at direct fire level.
Needless to say, because of that and his crying almost every night because he missed his wife, he was sent to an army field hospital and evaluated, then sent home. Although he missed the actual ground war, he was still awarded a combat patch and then later kicked out of the army.
Last I heard of him, he was a car salesman somewhere in OKC.
