If anything that ammo, will be the limitting factor. Scope mounted properly, off of a good rest, you should be right around, maybe a little over 1 inch. Keep your brass, and reload the same brass, necksize only, using better bullets, you'll probably be around .6-.75" maybe a little better. All of this assumes you are up to the challenge. I hope the 300WM isn't your first rifle, it was mine, it beat the crap out of me for a while before I learned how to use it.