Just picked up this unusual Model 176 from a friend. The barrel has been shortened and threaded for a very stoutly built compensating device that must weight three pounds all by itself.
Here's the big fella:
And here is the compensator:
I went to the FAQs to attempt to determine whether this is an SB1 or SB2 frame, and my conclusion is SB2, based on the smaller firing pin hole and the machined receiver floor:
Serial number starts with AT.
Do the experts here concur that it is an SB2?
Thanks.