On a gun where the chamber was a hair advanced compared to the forcing cone I could see a rather strong hit as the bullet passes from the cylinder to the forcing cone occurring. And with all the recoil energy pushing and pulling the stop bolt might just jump out of the notch enough to let the cylinder kick back and then relock in the previously fired position.
Certainly there must be some radial kick to produce this. And the only place I can see the radial kick coming from is some throat to forcing cone mis-alignment.
Yes? No? I'm not a proper wheelgun smith. Nor do I play one on TV. But I do stay at Howard Johnson hotels to increase my online believability....![]()