mercury recoil reducers and limbsavers on those.
I believe these will help with the shotguns as well. I couldnt stand my 870 w/ 3in turkey loads; picked up the Rem supercell recoil pad, and it felt like it cut the recoil in half. A twenty gauge with a good pad, especially in a semi, would be a smooth shooting SOB. If your going to be shooting an O/U the pad and mercury should keep it at a tolerable level as well.