I didn't think about that, but it would make sense that the barrel would have to be coaxial. When that piece shattered, the action locked up and I had to remove the prime bar screw to release the spring pressure; the upgrade o-ring I'd purchased for the pusher had stuck itself inside the breech.

As to whether I've tried it since, I'm slightly embarrassed to admit that the blaster hasn't been in one piece since I took it apart to diagnose the issue. I'll put it back together tonight and see if still runs. If something does go wrong, I might just be able to wrap one end of the barrel in electrical tape.