Thanks! I think RST shells sound like the best bet.

Since the gun is proofed for 2 3/4" would you recommend shooting RST "Premium Grade" 2 3/4" shells? I know you can also shoot 2 1/2" shells out of 2 3/4" chambers - wasn't sure whether I'd get better or worse performance that way. I suppose one way to find out is to buy both and give it a try.