I can't get my .308 AAC-SD to shoot. Replaced the stock with a magpul hunter, and swapped the trigger for a timney 510. Best 5 shot groups I have shot are 1.25 - 1.5 inches at 100 yards. That was with 168 FGMM, but I have tried probably 20 different factory loads. I don't hand load, but I was...