Rate of Twist for Barrel chambered for 223 / 5.56

GooseGrease

GooseGrease

New member
Hey Reloading and Ammo posters
About a year ago you guys on this forum gave me some great advice about rifle twist and bullet weight. I was buying a 22-250 and wanted to shoot the heavier gr. bullets. You folks unanimously steered me towards the 1/12 twist barrel. Again, great advise. I went with the Savage model 12 and haven't looked back since. Now here is my next question. My son and I have really gotten a taste for predator hunting since making our purchase of the Savage model 12. Do the math, 1 rifle 2 hunters ??? We are now in the market for an AR 15 model in the 223 caliber. As I learn more about this cartridge I see that it is also the same as the 5.56 but not as hot of a load. So far we have been recommended to narrow our choices down to a AR that shoots both cartridges. With that said, is there a specific rifling twist that we should be looking at as in the 22-250? If it matters any we are looking at the 16" barrel but could be persuaded to go longer if necessary. Unlike the 22-250 we are not as concerned about bullet weight as the rifle will be used for closer quarters. Your thoughts please.



 
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I would go with a 1:8 twist. I think it would almost be best to figure what weight you wanna shoot?

I can shoot anything from 40-80 with a 1:8 twist. At least that is what I have tried.
 
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It REALLY depends on what bullets you want to shoot.
If you are wanting lots of varminting fun on the cheap, DO NOT go faster than a 9-twist.
Varmint nightmare/Dogtowns(same bullet) have a RPM ceiling of about 240,000 rpm. Do the Math(see below)
Muzzle Velocity = MV

MV * 720 / Twist = RPM

So with a 9-twist gun, you can only shoot them 3000 fps. They provide very good results at those moderate speeds, but be aware you can easily twist them apart.
 
Originally Posted By: DarkkerIt REALLY depends on what bullets you want to shoot.
If you are wanting lots of varminting fun on the cheap, DO NOT go faster than a 9-twist.
Varmint nightmare/Dogtowns(same bullet) have a RPM ceiling of about 240,000 rpm. Do the Math(see below)
Muzzle Velocity = MV

MV * 720 / Twist = RPM

So with a 9-twist gun, you can only shoot them 3000 fps. They provide very good results at those moderate speeds, but be aware you can easily twist them apart.

Not to be rude but have you actually done the testing on that?

I make projectiles for my AR 1:8 .223 that are made form 22lr brass. Yes 22lr brass. "THEY" say not to push it past 3,200 fps or the projectiles will twist apart and almost dissipate at 100 yards.

This is not true at all. I can get accurate loads at 3,350. In fact my best loads about half of MOA at around that spped if not higher.

I know of guys who push them at 4,000 fps. Now granted they are not as accurate as they are at 3,500-3,600 fps for them in 22-250 but still do not spin apart.

 
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I can't comment on the fellow above, but for me about 1 in 5 of the varmint nightmare extreme hollow point bullets would blow up in a 1:9 savage 26" barrel in 223, but the soft points were fine.
 
My AR and Savage are both 1-9" and I can shoot 40g to 69g with either. I usually stay in the 52-60g range though. I wouldn't worry about the 5.56 vs .223 thing, just find the exact AR you want and go with it.
 
+1 on the 1/9 twist...I have two ARs and for Prairie Dog size shooting, I can use 40gr ballistic tips with excellent accuracy and move up to 60+gr rounds for hunting situations for bigger game...
 
Not quite 50 /50 but real close.
1:8 = 4
1:9 = 6
I suspect if there were that big of a difference the choice would be more obvious.
 
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Originally Posted By: GooseGreaseNot quite 50 /50 but real close.
1:5 = 1
1:8 = 4
1:9 = 6
I suspect if there were that big of a difference the choice would be more obvious.


The "1/5" was not a twist rate, he was saying one out of five bullets.....


Put me down for 1:8 and one for 1:9, not much differance when it comes to a mag fed rifle. A one in nine can still stabilize the heaviest bullet you can load to mag length.
 
There was a detailed article in a recent magazine, maybe 'Shooting Times', that compared different twist rates with 223 rifles.

The 1/9 actually scored rather high, it may of been on top, though not by a whole lot. There were a few variables though, like some of the guns may just be more accurate with most reasonable weight bullets.
 
if you are buying the gun to shoot varmints, i see little need to stabilize a bullet bigger than 55gr. the larger bullets are going slower, and their construction is usually for targets.
if varmints are the primary target, with larger game such as coyotes a possibility a 1-9 twist would be ideal.
 
1/9" twist.
This is what all my .223s have been in since 1979 and I shoot over 9k rounds a year into p-dogs alone. Perfect for 40-69g bullets.
 
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