I have had more than one rifle do this. Shoots extremely good. Then groups start to open up and fall apart all together. Clean the barrel but the rifle will not shoot the same load. Groups will be terrible. Even after shooting lots of rounds to foul the barrel. Just had a 25/06 go from shooting 1" groups at 300 yards to 2.5 inches at 200. So cleaned the barrel. We back to range, shot 7 fouling shots, then back to the good loads. 5 inch groups at 200 yards???? Back to load developement again, sucks. Rifle was going to Montana Saturday but not any more.