Lorne, I have a standard 22-243 Winny. I use RL 25 topped with a 75 Amax. Cant remember what charge I use at the moment but Acklyman is correct on swabbing the bore after about 20 or so rounds. Mine will shoot -3/8 @ 200 yards from a clean bore upto around 20-25 rounds. Then for some reason groups will open up to around 3/4". Swab bore a few times and right back down to -3/8" !!! Just a little info for you.