SLOOOOW Twist AR barrles?

[Wolfdog91]

Anyone know if a company currently producing ( not interested in old stock ) some very slow twist are barrels in .223 or 5.56 on a non custom deal? As in they have them ready for purchase ? And when I say slow I mean 1:12 at the least 1:14 preferred .
Thanks

[M-Tecs]

The AR retro guns used them. If you want a heavier contour you will need to custom order.

https://www.brownells.com/gun-parts/rifle-parts/rifle-barrels-parts/ar-15-m16a1-retro-carbine-barrel-assemblies/?sku=100020999

In the past Krieger made me 13 twists. https://kriegerbarrels.com/twist#ar15

[Nobade]

You might talk to Shilen. I've used a few of their 1:14 blanks to good effect making AR barrels, maybe they would build you a full drop in one.

[popper]

Original was 1:12 then they over spun it so you got tumbling when it hit something. I.e., more damage on the perp.

[Calamity Jake]

Rock River produces a 1 in 12 twist ,as I have one, shoots the Saeco 225 70 gr rn real well
My barrel is a 24" heavy stainless, don't know if they have a shorter/ lighter version
this is 2 10 round groups at 100 Yards

[Barry54]

Anyone know if a company currently producing ( not interested in old stock ) some very slow twist are barrels in .223 or 5.56 on a non custom deal? As in they have them ready for purchase ? And when I say slow I mean 1:12 at the least 1:14 preferred .
Thanks

Green Mountain has 1:12 in stock at the moment.

http://www.gmriflebarrel.com/GMRBItem.aspx?Item=GM-M15

[Barry54]

And they have a 1:14 twist for $195

http://www.gmriflebarrel.com/GMRBItem.aspx?Item=GM-M14&ReturnURL=/military-barrels/ar-15-/-m16-/-m4-rifle-barrels&Category=2756c0ce-174b-46fb-bc11-6723e893d5ea

[Hannibal]

Original was 1:12 then they over spun it so you got tumbling when it hit something. I.e., more damage on the perp.

Ummm.... NO.

Understabilization caused the yaw effect.

[M-Tecs]

Original was 1:12 then they over spun it so you got tumbling when it hit something. I.e., more damage on the perp.

The originals were 1/14 specifically to have marginal stability with the M193 55 grain ball. Winter testing revealed that a 14 twist was to slow for winter use. They went with a 12 twist until the M855 62 grain steel core NATO loading required a change to the faster 7 twist to stabilize them. The problem was the 7 twist over spun them so they DID NOT normally tumble thus reducing effectiveness of the system.

http://retroblackrifle.com/index.html

[Larry Gibson]

The originals were 1/14 specifically to have marginal stability with the M193 55 grain ball. Winter testing revealed that a 14 twist was to slow for winter use. They went with a 12 twist until the M855 62 grain steel core NATO loading required a change to the faster 7 twist to stabilize them. The problem was the 7 twist over spun them so they DID NOT normally tumble thus reducing effectiveness of the system.

http://retroblackrifle.com/index.html

Correct, the original twist was 1/14. One small correction; the M855 62 gr bullet will stabilize just fine in 10" or faster twists. The 7" twist was needed to stabilize the much longer tracer bullet which needed a "burn" out to 600 - 800 meters. The ammunition an appropriate barrel twist was originally developed to meet specifications for the SAW [M249] then the barrel twist of the M16A2 and subsequent variations were given the same barrel twists. Interesting to note, back in the early/mid '90s, the Marines ordered from Colt quite a few M16A2s with 9" twist barrels because they gave better accuracy, especially at 500 yards, with the M855 ammunition.

[M-Tecs]

Correct, the original twist was 1/14. One small correction; the M855 62 gr bullet will stabilize just fine in 10" or faster twists. The 7" twist was needed to stabilize the much longer tracer bullet which needed a "burn" out to 600 - 800 meters. The ammunition an appropriate barrel twist was originally developed to meet specifications for the SAW [M249] then the barrel twist of the M16A2 and subsequent variations were given the same barrel twists. Interesting to note, back in the early/mid '90s, the Marines ordered from Colt quite a few M16A2s with 9" twist barrels because they gave better accuracy, especially at 500 yards, with the M855 ammunition.

Thanks for the additional info. I've always read that the overly fast twist was solely to provide better penetration for the M855. Stabilizing the longer tracer rounds makes more sense.

[PopcornSutton]

I watched Green Mountain Barrel's site for a long time at those 14 and 12 twist barrels, and they were always out of stock. Gave up. So I bought another lower, upper parts, and turned down a retired 6mm 12 twist BR barrel, and have a 6x45 reamer in the mail to me. This should be a lot more funner! And I have gads of misc. 6mm bullets for let fly.