Try getting a mercury recoil reducer for it. The make ones specifically designed for over/under shotguns that fit in the chamber of one barrel like a snapcap. A lot of guys use this type at the trap range, and the beauty of it is that it can simply be removed if you want to use the second barrel without any hassle. I have a 5oz Hg recoil reducer in the buttstock of my BPS and it really takes the edge off the recoil. I put mine in because I shoot a lot of trap and I' ll go through a minimum of 100 shells of 1 1/8oz #8 target loads (call me a brute for punishment, but I like putting a LOT of shot down range). I have been known to shoot as much as 8 rounds of trap (200 shells) in an afternoon, and I never go home with a sore shoulder.

Mike