Originally Posted by
Night Crawler
Cantilever mount is most likely your problem.
I think Flags alluded to the same issue and I concur. It would seem logical to me that large and inconsistent groups could boil down to a scope/ mounting issue. When I decided to get a slug gun I eliminated consideration on all cantilever mounts due to what I considered to be a very fragile mount considering the hard shock brought out by a slug gun. Shooting from a bench with 3" mags with my new model 37 gave me my first and only idiot cut the first time I shot it. I was shocked and totally surprised at how hard it thumped me. I too came to the realization that there was no reason to go with 3" loads. If I had to set up another I would probably go with a 20.