Hi, I have found better luck with 165gr from mine. I absolutely love the DedNutz rings, I have them on many rifles including Tikka's. They are a 1 piece design that screw to the 4 pre-drilled holes in the top of the receiver. They are available for around $48 from Midway. They are a great product. I have tried the Warnes and Talleys, which also work. I just prfer the 1 piece mount, very solid and they don't add much weight either. The stock Tikka rings don't do so well on the 308, although they are fine on smaller calibers.