By the time of my service some 1927 M1A1 Field Howitzers were still around for ceremonial firing at flag-raising on national holidays, so I got to fire one. On those details we wore large brass buckles on our pistol belts. One Memorial Day I spent all morning polishing my belt buckle, and as soon as the piece fired and we opened the breech, the smoke engulfed it and turned it instantly to a dingy grey.