I have a 5 year old 7mm-08 plastic BAR. 1st 2 shots are very decent. about 1", I'm happy. After the barrel gets warm, and then hot, the shots start stringing in an arc... like a crescent moon. 4-5 inchs off center at 100 yards. If I let the barrel cool down, the shot returns to center. I know it's a hunting rifle, not a range gun. But I like to sit at the range practicing for hunting season. and put 20 rounds though a sitting. Can these guns be smithed to be accurate when hot ?