When I let it cool down, the point of aim climbs back up. Then, as you might expect, it settles in as it warms up.

It took me a couple of trips to the range to figure this out. I have a nice scope, but I thought that the relatively inexpensive mounts I put on the rifle were part of the cause. Every time I went out, I'd take a shot, see that my first shot was high, adjust the scope, take another shot, be right on, then start to be a little low. I'd have to adjust every other shot or so until I had 8-10 shots fired, then everything would steady out. I'd leave the range pleased, because my last two or three groups would be pretty nice, and I'd think I had my "scope issues" sorted out. Now, I realize that it's the rifle, not the scope or mount.