These butt cuffs are great for providing some protection to the finish, for looks, and for providing more grip to your body when you shoulder the long gun, and the loops are handy if you're using the rifle for non-cowboy action stuff (hunting, plinking, etc.).
However, you must keep in mind that if you store ammunition in cartridge loops mounted on the firearm's stock or forearm, you may not use it during the match to load from. All ammunition required for loading/reloading during the course of any stage must be carried on the shooter's person or be safely staged as required by stage instructions.