I did a dangerous thing to an old pin sterlingworth 12 with short chambers to boot.I have old eyes and can not see close and loaded two three inch magnum Winchester turkey loads by mistake,do not remember the load ,but it was the heaviest ones! When i test fired the gun it had really heavy recoil and doubled and the snap on forearm fell off.Did not hurt a thing except my pride! I suspect the recaseing of the frame caused your failure! Sorry for your loss! Bobby