I have a Model 70 Winchester 375 H&H that was made in 1960. I have been tinkering around with this thing for quite a while and can't get it to shoot to like it should. It will shoot light bullets with light powder charges pretty good, usually under 1.5 moa. Such a load is a 250 gr. Sierra at 2500 fps. However, when I turn up the volume groups open up to 5-6 moa. Even most factory ammo that I have tried looks more like a shotgun with 00 buck from about 20 yards. I am convinced that the higher the chamber pressure the worse the accuracy. Let me tell you what I have tried already. I have tried three different scopes, replaced the stock with a synthetic and free floated the barrel. Two sets of mounts/rings. Numerous combinations of bullets and powders. Any other ideas? I have been told that it could possibly be uneven locking lugs causing the problem but I smoked them and cycled the bolt and both lugs do seem to touch, although not across the entire face of the lugs. I am about to sentence this rifle to a life as a collector, but I have a hard time leaving a gun clean too long!