I've been around a few different 550s, 7mm rem mag, 300win, and 243win. I've yet to see one that won't hold MOA @100yds with a competent trigger man. The 7mm mag was a bit picky about ammo, but the 300win and 243 ate pretty much anything you fed em' and spit it into an inch or better. As Tripleduece said, they are a bit on the heavy side but not overly so.