When a barreel goes sour, normallly the groups open up randommly..
An equipment problem , ie. loose screws , brass, etc willl not.
That means that you will have clusters of two or three bullets and flyers.
if it is the rifle and it is still stilll printing under 2" at 100 yards, quit shooting it at targets and shoot it at animals only.
They won't complain any louder if you hit them
in the 7 ring instead of the X!!
Cat