Hey guys, I know a couple of you are a lot more experienced in guns in general and ARs in particular. I'm currently building an AR; it's my second one I've owned but first I've built. I'm open to either building my upper or buying a complete upper if I can find exactly what I want, but I'm leaning toward building right now. My question is about the rifling twist. I've seen everything between 1 in 7 to 1 in 12. In your experience, what's best for firing a 55gr FMJ round in an 18" barrel. I'm not looking for ultimate range (if that were the case I'd be building a .308), but for solid consistent accuracy out to 250 meters or so.
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