I owned couple Ar15s in the past and didn't like it at all. Sold it, when with the Ak and loving it. Now I want to build my own Ar15 just because AR look sooooo taticooool. When I looking into the upper of an AR it said 1/7 twist, 1/16 twist.... I really dont know what they mean by twist.....I look up google and it gave me thousands of answer... Make me more confusing. Please explain to me what twist in the barrel are for.