Juice9869

Hello, I'm new to this forum, and I can't seem to find any post that match my issue. I have a Saiga 410 with a Promag 30 rd drum. It cycled the first round, but it jammed. I was using Remington 3 inch High Brass, and it would fire, but then the shell would get crushed and wouldn't eject. Does anyone know what might cause this?