Originally Posted by Rusty

Next time out. Check your zero. Shoot slow. Take your time. After that. If your group doesn't change. Shoot a rapid bunch or two. See what happens to your group. If it starts to string out. Vert or Hor in a some what straight line. Something is pushing the barrel when it gets hot. Let the gun cool off. Then shoot a slow bunch again. And see what the group looks like.

Have a 7mm Rem Mag that would shoot dime size groups all day long. Long as the barrel didn't get too warm. Once warm, it would start to go vert with each shot. Found that the stock had a tit at the end that just touched the barrel. When the barrel heated up. It would push the point of impact up with each shot. Since I fixed it. It will shoot dime size groups no matter the barrel temp now.