520, as you stated that is what the S&W person said. Our 12 probably was just torqued too much when it was assembled. It cracked right beneath where the bottom of the barrel goes into the frame. Just like cars. One person can get a lemon from the factory & another guy can get a jewel. I think it could be that monday thing.

I guess everyone has to decide for themselves what they want to put thru their gun & what can happen or not. Osprey's tests sure prove that.

Lefty Lar