Dave

When you cleaned her before shooting, did you forget to tighten down that tiny set-screw by the trigger guard??... it may have loosened more during shooting & fell out. Also check the two knockout pins around the trigger housing -- make sure they' re secure.

A better, tighter fitting bullet that' s still cheap to shoot is the Buffalo Ballet (50 for $8). They will smooth-out any imperfections faster than roundballs.