Ok, here's the deal. I was firing my newly converted saiga 12, that I just finished. I was using a MD Arms 20 drum. It was loaded with federal's military grade buck shot. I inserted the loaded mag and released the bolt. Took aim, pulled the trigger, bang, the empty shell ejected, and the new one loaded. I pulled the trigger and the trigger didn't move. I cleared the loaded shell thinking it short stroked or there might be a misfeed. After pulling the bolt back and clearing the recently loaded shell with a new shell. She fired just fine. So instead of semi auto, it became a bolt action shotgun.