I'm shooting .308 168gr Federal & Black Hills Match ammo. My 100yd groups average 9/16", with shots between 3/8" & 3/4". Occasionally I squeak out a 1/4" or smaller group. Occasionally I shoot a 7/8" group. I'm shooting prone off a sandbag w/a rear squeeze bag. My rifle is a GA Precision. My scope is a Schmidt Bender. For argument sake, lets assume that the scope is installed properly. Is that about all that I should expect from factory ammo or do I need to work on the fundamentals?