SDD-UP

Babis, Only speculation on my part. I do not own a Shadow 2 yet, but will go look at my 85 Combat. How many rounds through your gun? It's not just the frame, but how hard/flexible is the pin? If the force through the pin could be directed through the middle of the frame material instead of through the full length of the hole it would reduce the twisting induced in the frame and likely eliminate this type of failure. There is limited space to do this and it is just one more possible solution.

I am a mechanical designer by trade (not an engineer) so take this for what it is. In my opinion this frame cracking/breaking failure is most likely caused by A - improper heat treatment of the steel (too hard) and/or B - improper steel alloy selected (too hard/brittle for this IMPACT no matter how it is heat treated) Removal of the top portion of the hole is a solution, but probably not the BEST solution in my opinion. I think CZ certainly has the resources to figure this out and come up with the right solution.