The 3.5" guns do pack a punch but I just wear a good insulated coat when patterning off the bench. Once I' ve found the load I like I then will shoot sitting off the ground simulating a shot in the woods. I wear my turkey hunting clothes when doing this. Another solution would be to send your gun to nitro company and they will find what shoots best in your gun. But man this is going to cost you and you still would need to shoot the gun for yourself. Here is their link:

http://www.nitrocompany.com/pattern.htm