I started working on my wife's 243 again. I've decided it does best with light loads, one grain over start. At middle loads it starts flattening primers and opening the action (which realy stretches brass.)
last week, at 100 yards I shot a 3 shot string, 1 minute apart. The 3 shots hit in a vertical line, each 2 inches lower. After a 20 minute cool down, the fourth shot hit near the first. Five minutes later, the fifth shot hit 2 inches below the cool barrel impact.
Fro my wife to hunt with, I can deal with that. But its no fun for me to shoot it at the range. I can shoot one shot, then shoot a few other rifles, and hope I get the handi into the bags the same way.
Why is point of impact dropping with barrel heat? I wonder if the chamber area of the barrel is heating and expanding unevenly, lifting the front of the scope. Or maybe changing forestock pressure?
Has anybody found any accurizing tips to stop this? Maybe the techniques in "accurizing the factory rifle" that one of the members sent me?
If I'm stuck with a rifle that can only shoot mild loads every 20 minutes, I can live with it, but it would be more fun to shoot it like my other rifles.