Breaking in my barrel on my new gun. A Nightforce scope sits on top with the Sako 3 ring tactical mount. Shooting 180 gr reloads for the barrel break in procedure and so far best i get is 3" groups at 100yds, hopefully things get a lot better because this is by far the most expensive rig I've ever purchased. I was very carefull to mount scope properly and even used a small amount of blue loctite on the screws but something must be moving. The 3 ring mount is equipped with plastic or nylon inserts that go between scope and rings, this was purchased used but I don't see a problem with the scope shifting within them. All try some match handloads and see if things tighten up!! Your thoughts or coments would be appreciated.