My first AR was a Colt Gov't Carbine, ca. 1989. It had a 1/7" twist and would group its best handload (R-P match-prepped cases, W748, CCI Benchrest primers and a Hornady 62 gr. HP) into 1/4-inches @ 100 yards all day. The rifle had an ARMS mount, Tasco target scope, Harris bipod and was fired from a bench with sandbags supporting the buttstock..