I put Limbsavers on most of my shotguns, have one with a slip-on (?name) that's OK, too. LS is worth the $50 or so, I think they make some slip-ons too.
I've got a full-size pump, FullSize semi-inertia, 19" gas-semi, 14" pump - all with full stocks. I'm 72 and 160 lbs, so I'd rather the LS take the beating ;-p