That happened to my Thunderbolt . I was able to pry the round out , tried to pump another in same thing happened , so I took it back to the dealer still jammed and loaded. Got my money back dont want another one. Maybe 6th generation .
Now for your problem , look at some of the posts on the Tauraus and try to get ahold of John Boy he was very knowlegable and helpful about this particular problem. Has to do with Overal Length of cartridge , but he cqn explain it and seems to know how to make the gun work. Good luck Sweettooth out.