The Shaws I have seen foul pretty quick but make good shooters when the barrel has been broken in and is clean. If you have a 1:10 twist, try a 168 -180 grain and us some Reloader 15, Varget, IMR 4895, maybe even 4064 and see if your groups close up. I know there are guys that can get the 1:10 to shoot light bullets but I cant. Plus the BC on the heavier bullets is better for windy days