A question for AR15 barrel experts

[lyle c]

With a 20" barrel, what rate of twist would be ideal for ranges between 200 - 350 and why? I'd like a detailed explanation since this is a pretty grey area for me. Thanks!

 

[Paulinski]

Rate of twist has no effect on a range. You want to shoot a heavy bullet so I would recommend 1/7 twist rate and 77 grain bullets.

 

[Assyrian]

With a 20" barrel, what rate of twist would be ideal for ranges between 200 - 350 and why? I'd like a detailed explanation since this is a pretty grey area for me. Thanks!

Expert?? Here?

You want a detailed explanation, but you have not given detailed specifics.
What kind of barrel? Crowned? Muzzle attachment?

What Ammo are you shooting? Caliber? Grain?

What are you shooting at? Paper? Hunting?
Do you need Penetration along with your accuracy? Large wound channels?

You need to know what you want before you ask people to explain to you why you want it......

 

[beltfed]

If you are refering to accuracy, there is quite a bit of data out there on the US Army Marksmanship Unit.
Last I read, the AMU uses 1:7ish barrels firing 69gr. SMKs (in Federal Gold Medal Match factory ammo) out to and including 300 yards and 77gr. SMKs (handloaded) beyond that to 600 yards.
This info is at least a few years old, so I'm not sure if it is exactly current.
This is also all relating to a specific discipline, so take that into account.