1/7 or 1/9 twist?

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I am about to order a rifle kit for an AR. I already have the stripped lower. I am looking at the 16 inch barrel for it. It will be .223. I am a little confused on which twist to get. I could use some advice on which one would be the best choice for my weapon.

Thanks
 
It depens on what you will be shooting.

1:9 is the best choice of you plan on shooting military surplus or commercial ammo under 65 grains or so. 1:7 if you are pnly going to be shooting heavy bullets.

5.56twist.jpg
 
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I have a Colt target with 1-7 twist and it 's getting pretty tough to find 62 gr ammunition to run through it. Granted it shoots 55 gr stuff just fine for plinking, but for best accuracy I need to use at least a 62 gr bullet. I don't reload and I rely on Gander Mtn and other such places for ammo. I have not been able to get anything with a 62 gr bullet for about 6 months now. Had I known then what I know now I would have went with the 1-9 twist.

RH
 
The only folks I recommend a 1:7 to are those that are building a 20" NM to use for high power. You need it for the big SMKs at 600yrds. If that is not the intended purpose of the rifle get a 1:8 or 1:9

Pete
 
I have both 1:7 and 1:9. The 1:7 can do everything the 1:9 can do and more.
You cannot beat Federal Gold Match 69gr or 77gr in the 1:7.
Hornady TAP (not FPD) 75gr is great too.
 
lone gunman said:
I would go 1:9 also... it will shoot everything from 55-69g very well, and I have shot 75g bullets through mine without problems or diminished accuracy.
The misunderstanding is that 1:9 is optimized for 62gr. SS109 but that same bullet would be 71 grains if it was all lead construction. I went with a 1:8 because I want to try out 77gr. mk262 type stuff but I'm not interested in using tracers in arctic conditions and it's what they had in stock for stainless barrels at the time.

hags said:
The 1:7 can do everything the 1:9 can do and more.
yeah but a 1 in 9 twist will last longer. 1:7 is not superior, it's a durability vs. versatility thing.
 
1:7 is not my pick for light bullets. If you are going to blast rodents, you're better off with a slower twist. If you are going to shoot barely mag length heavies, get the fast twist. If you are going for military surplus, see the chart I posted above. 1:9 is a compromise twist that shoots M193 and M855 equally well.

There is no perfect twist for all situations. Pick your use, then pick your twist.

I like Milsurp, plus 52n SMKs when I want to exterminate Mr. Gopher. 1:9 is a good compromise.
 
For an AR, and .223 in general, what I would consider a true "varmint" barrel twist would be 1:12, something that can shoot the explosive lighter weight bullets accurately. Mr. Gopher gets 1:12 for bullet weights up to and including 60gr.
Extremely accurate for weights from 40gr to 55gr!
For everything else 1:7 fits the bill.
 
yeah but a 1 in 9 twist will last longer. 1:7 is not superior, it's a durability vs. versatility thing.

Uh, the assumption that you'll burn out a 1:7 faster than a 1:9 has been debunked along time ago.
That has more to do with velocity than twist rate.
 
1/9 works best for most people, since most shoot 55gr ammo. Don't get a 1/7 unless you're planning on shooting mostly 70+ grain ammo.
 
Between the 1:7 and 1:9, I like the 1:7 myself. As Guntech's chart shows, the practical difference in accuracy is small between a 1:7 shooting 55gr and a 1:9 shooting 55gr. The 1:7 will give good practical accuracy with a wide range of loads from 45gr to 77gr. The 1:9 may work with some of the heavier loads or it may not.

You might also consider 1:8, which is what I am using in my favorite rifle right now with good results.
 
Between the 1:7 and 1:9, I like the 1:7 myself. As Guntech's chart shows, the practical difference in accuracy is small between a 1:7 shooting 55gr and a 1:9 shooting 55gr. The 1:7 will give good practical accuracy with a wide range of loads from 45gr to 77gr. The 1:9 may work with some of the heavier loads or it may not.

Absolutely, and those who shoot for accuracy rarely choose a 55gr bullet. So, you can "plink" with it and get really serious on the accuracy end of things with the 75gr, 77gr and 80gr tackdriver bullets and loads.
 
what bart said, except instead of 45gr to 77gr, it's 45gr to 100gr
 
I wish someone would put a fast twist in other 22 centerfires. I want to shoot heavy Bergers out of a 22-250, but everything out there is 1:12. :(
 
I say lean on the faster side of twist rates available. With a 1:7, you can shoot any bullet that can be seated in a case at mag length, and most bullets that can't.
 
Uh, the assumption that you'll burn out a 1:7 faster than a 1:9 has been debunked along time ago.
Not that i'm calling you a liar but please give me a link or some information to back it up. From my point of view the assumption seems logical given that it's impossible to overstabilize a bullet, why wouldn't rifling twists just be as quick as possible? why do we have such a wide variety of twists if there's no reason not to go as quick as possible?
 
I say lean on the faster side of twist rates available. With a 1:7, you can shoot any bullet that can be seated in a case at mag length, and most bullets that can't.

I agree. There is no penalty for going with a 1/7' twist, unless the shooter plans to use the thin-skinned, 45 grain-and-lighter varmint bullets. There is no practical accuracy degredation with 55 grain surplus, while the heavyweights can be accommodated as well. It's just more versatile.

vanfunk
 
I have an Lewis Machine & Tool Company 16" AR with a 1/7 twist.

Off sand bags, I can shoot 5 shots into one inch at 100 yards with iron sights. I notice no difference between 55 gr. and 62 gr.

The 69 gr. and 77 gr. Sierra Match Kings are outstanding. Off sand bags, I can group between 3 or 4 inches at 200 yards with SMKs and iron sights. With 55 gr., I can get a soccer ball or basket ball sized group at 200 yards.

This is just me. I don't use a fancy mechanical rest. I use sand bags, but my breathing affects my sight picture. The 55 gr. ammo I shoot is the cheap full metal jacket or jacketed soft point by Remington and Federal. SMKs are built to higher standards than the cheap stuff, so my AR could very well shoot 55 gr. just as accurately.

This is my experience with practical accuracy from an AR.
 
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