To concur with GK, my Montana in .300WSM, I bought used from a guy that I'm sure hadn't put 20 rounds through it. I had no loads to start from nor data to work with so I began with what I could find on the internet. I've probably only put 5 or 600 rounds through it but it shoots way better today than when I got it and I ended up using the very first load that I came up with as the one it likes the best. Have no idea how it would shoot with factory ammo because I enjoy reloading too much.