Several years ago a older gentleman joined my club and he bought himself a M1 .
I got a semi panic phone call with him on the rifle range with a live round 95% of the way into the chamber but he couldn't fire it and he couldn't pull back on the op handle.
I only live 4 or 5 miles from the range so I tossed some tools , hammers and blocks of wood in the truck and headed down to the range.
My thoughts were of how hard I dared to wack the op handle and what the general feeling was by those in the know.
As I pulled into the range my friend came out and said he had got the stuck case out and was only waiting for me to arrive with the GI style chamber brush so we could clean things out.
I of course asked how he cleared it .
My friend answered "the Army way" He had passed through West Point close to 60 years prior and he remembered the method he had been taught was to place the butt on the ground , lean the rifle out a bit so it wasn't pointed at your face and stomp with full force on the Operating handle.
Took him a couple of minutes to remember what he had been taught many years ago. Not push down . not step down but stomp like hell.