My first AR15 was a 1987 vintage AR15A2 Gov't., serial # 000214. With an ARMS mount, Bausch and Lomb target scope and a '6-9" 'Harris bipod(with bipod mounted just forward of the forward receiver pivot pin, I could get 1/4-inch groups from 100 yards using my best handload. I never touched the trigger OR replaced the forearm. See how it shoots NOW...before you go swapping parts.