I've got an older 12bvss in .308. Lately i been having problems getting it group well,I'll get 2 shots that touch then all of a sudden it will throw one or more rounds an inch or better away from previous shots.

This happens with quite a few different loads nothing as far as loads seem to make a difference. How much clearance is needed at the tang?

Also I have not swapped scopes yet but might get on that tomorrow if i can. I had to fix the front pillar area by bedding it.

An other suggestions as to where to look for problem areas this rifle has shot ragged one hole groups from time to time but now it is not consistant at all and it's starting to suck.

I've tried wc846,varget,ramshot tac and imr 4064 with 168 nosler custom comps. seated all the out to the lands back to 2.800" that the manual states.

One thing that was done was a brake was installed and the point of impact will change greatly when zero'd with it on then removing it. Could the brake disturb harmonics enough to where it is not going to group with it on? Also it does this off a bipod and rear bag and also off front and rear bags.