280 Rem. but the rifle has a lot to do with it. M700 Stainless Synthetic Mountain Rifle with a Luepold Vari X 3-2.5-8. The trigger has been reworked, the bolt lugs squared up, the muzzle recrowned, and the action is pillar bedded. Shoots 1/2" 3 shot groups at 100 yds. with my handloads.