I'd go to Yahoo and search for "shotgun recoil reduction". There's many a gadget, including mercury tubes, which really work. Then I'd encourage Dad to get a gas operated autoloading 20 gauge and stick a Sims or such aftermarket recoil pad and a mercury tube on it. Then I'd get him to promise to reduce his range to 15-20 yards. You can instantly kill a tom at that range with a 1 oz. 2 3/4" 20 gauge HeviShot, and there is virtually no recoil to begin. With the added mercury tube and recoil pad, Dad should be good to go.