I've got a Mark V in .257 Weatherby. Bought a couple boxes of their 100 grain, hornady bullet factory ammo when I got the rifle (their cheapest load in that caliber). It will consistently group 3 shots within 1.25" at 100 yards and dropped a deer in its tracks last fall. Since then I've just been shooting handloads (I enjoy handloading, and that Weatherby ammo is expensive!).