Longrangers
Well-Known Member
Did you check for group size at longer distances?The only other thing I can add is my .257 Weatherby Mag doesn't like boat tail bullets. She was a finicky b**ch to get to shoot a tight group with. She only likes flat base bullets. IF everything you have tried are boat tails try a flat base & see if it makes a difference. Mine likes the Barnes TSX 115 gr. flat base (they make boats also) Best of luck to you.
Some won't shoot very well at 100 but start to settle down at 300.