A dumb ass Ordnance Lieutenant took some of us out to the range at Ft. Lewis back in 1966 to shoot an old M-20A-1 3.5 inch rocket launcher. We had NO ear protection and my first shot with the dummy round took out one of the bleacher benches. I could not hear a thing for a week. :)
The Korean War vintage 3.5 inch Rocket Launcher called the Super Bazooka