I would suggest using an alternative to the factory rings. With my 6.5 x 55, the scope slipped forward in the front ring and the rear ring slid on the dovetail (only the front ring has a recoil pin). This happened with all screws securely tightened, and with a very mildly recoiling caliber. Switched to the Talley lightweights, and haven't had a problem since. Also used them on my 338 WM, with great results. My opinion is that they are a more efficient (less wasted material), stronger (4 screws per cap), and attractive choice than the popular dead nutz. But that's just one view