barrel twist rate question

[Dr. Tad Hussein Winslow]

http://www.flickr.com/photos/23922375@N04/3739013167/

Hey which of these would you guys pick for a new AR build: (1) 20" 5.56x45mm, 1 in 8", or (2) 18" 6x45mm, or (3) 20" 6x45mm ?

Leaning toward #1. Purpose is all-around / all-purpose rifle, about 70% defense & militia / 30% hunting.

 

[centraloklahoma]

I have shot hundreds of 52 grain hollow points (Federal Brand), and 55 grain FMJ (Federal, PMC, Remington, Winchester) out of Colt 1/7 twist rate barrels. One is a 16" lightweight and one is a 20" Match H Bar.

I HAVE NEVER EVER seen any of these rounds "DISENTEGRATE", "Break up", or "Come apart".

Targets hit from 100 to 400 Yards range showed good accuracy.

Additionally I have fired 50, 55, and 60 grain Hornady TAP out of the 16" Colt 1/7 twist barrel out to 200 yards with no issues.

CP

 

[swickey]

This Thread was extremely helpful to me.. I have been trying to figure out this for an AR build... Thank you everyone for you input.

 

[Ksmirk]

The only bullets I had issues with coming apart were the varmint nightmare bullets, 3175fps from the 1-9 twist Savage fine and they would come apart in the 1-8 AR. The 52gr match bullets would not come apart in the 22-250 the varmint nightmare bullets well you can imagine little grey poofs :-) Later,

Kirk

 

[KurtM]

Let me tell ya about a place, out in upper New York State, where the kids are really great, twistin the night away....hey

 

[Donald]

You might take a look at this sight. http://www.uslink.com/~tom1/twistrate.htm The length of the barrel has nothing to do with stability other than the velocity you get out of it. Decide what bullet you want to shoot and select the twist rate for that bullet. There is no "do all" twist for best accuracy. The length of the bullet has more to do with what twist you need more than the weight. Now that we have all copper bullets and some with steel cores that are lighter than lead cores. A 9 twist will probably come closer to shooting anything you need other that when you get past 69 grains.