I had a friend back in my teems that had the most "automatic" of these single shots I've ever seen. Every time he's pull the trigger the gun would then pop open and eject the spent shell. If he wasn't holding on or the tape had worn that held the forearm on it would them fall off as well. I used to give him quite a bit of "distance" when we were hunting.
Jim
My first shotgun was an old H&R single shot 12 gauge. I was ten as I recall. The recoil was so fierce, that when the gun recoiled the forearm would stay in my left hand as I toppled back. Each time I shot it I'd have to put it back together. Remember one time it happened and at the same time my right thumb accidentally pressed down on the opening button and I was left holding the forearm in my left hand. The buttstock/frame in my right hand, and the barrel was laying on the ground. Man I hated that gun. Don't ever make a kids first gun a single shot 12 gauge when he weighs about 80 pounds.