I love my M7, 20" stainless, .308, get about 2800 fps out of a 150 Ballistic tip, slightly more with a 140 Barnes. It'll take mulies at 400 yards across a canyon or whitetail out of a box blind from 40 yards. It's got a 2x10x40 Weaver on it, very versatile. Light for rough country, short for box blinds, fast to the shoulder in heavy brush still hunting situations, all around gun if ever there was and, unlike most compromises, it does it all very well. It shoots 3/4 moa for the first 3 rounds and after the barrel heats up, not much more.
Yeah, perfect conditions, I'd do 400 yards with it, no problem. I know the exterior ballistics and have 'em taped to the bell of the scope for reference in the field. I won't shoot any farther with my 7 mag, frankly, too many variables beyond 400 yards. Has to be a calm day with no up or down hill before I'd shoot THAT far, but I've taken a coyote at 370 with it, measured with a laser range finder.