Sr-15..

[JimmAr]

Now why would you put a 1 in 7 on a 16" Ar platform? Im curious to see what people have to say.. over at AR15.com testing it against alot of other production models it fell short on accuracy..

Is there military/factory ammo that will shoot well in these?

 

[sarduy]

Now why would you put a 1 in 7 on a 16" Ar platform? Im curious to see what people have to say.. over at AR15.com testing it against alot of other production models it fell short on accuracy..

Is there military/factory ammo that will shoot well in these?

a 1/7 twist is used to shoot heavier bullets like a 69gr, 75gr and even 90gr while the 1/9 is shoot better with lighter bullets like 55gr, 62gr, there is the 1/12 but that's for very light bullets like the 40gr, 45gr.

ETA: if you shoot a 75gr bullet in a 1/7 you will get great accuracy same goes for a 55gr from a 1/9 but not the other way around. the difference is small for a combat rifle or shooting human size targets but if you want to go moa, you need to match the bullet grain with your rifle twist for best performance.

 

[Zak Smith]

The 7 twist was to stabilize tracer ammo. 1:8 is good for any regular projectile that is magazine-length. Some Service Rifle competitors use faster than 1:8 twists for 80gr or heavier bullets, which they usually single load.