Bonr….Are you trying to use yours in a blowback 22 (just looking at the receiver in the photo)? If so, that may have caused the damage to the hammer "tail". The bottoms of the carriers are different enough, and the interaction with the hammer is also different enough, that the hammer may be impacting the inside bottom of the lower receiver. In that case it may also be stressing the hammer pin and egging the pin holes in the receiver. You'll want ot check both if that is the case. We used to have that problem when someone would install a NM hammer in a 9mm carbine (factory builds were all single stage), until we started ramping the bottom of the 9mm bolt assemblies, making them NM trigger kit-compatible (but no longer usable with our old 9mm single stage hammers).
Steve/RRA