PLease explain the twist on Ar15

[Benny503]

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.

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[ZachS]

It's a measurement of how much the rifling twists in the barrel.

Higher numbers (like 1:10) mean the bullet will spin slower after it leaves the barrel. Lower numbers (like 1:7) mean the bullet will spin faster after it leaves the barrel.

On a very basic level, lighter bullets work better with slower spins and heavier bullets work better with faster spins. According to my research, there are many other factors that come into play.

 

[best defense]

Exactly as ZachS stated. When the twist is measured in inches the 1 in 7 will be one complete turn in 7 inches. 1 in 12 would be one complete turn in 12 inches, etc.

I don't know what the metric designation is, but I'm sure there is one.

 

[spider]

I know that my 1:7 twist noveske upper, loves heavy grain bullets, I'm pretty sure outside of the rifling in a barrel, doesn't really matter to shooters, unless you're a sniper or perfect target shooter. Knowing what twist you have, the way the world rotates, and calculated wind speed is the stuff elite snipers know, but as long as I can shoot some cans from 75 meters, im happy.

 

[Benny503]

Thanks all, clear as crystal.... Now I am off searching for my first build AR.