AR: 1:7 or 1:8 or 1:9 barrel twists

Tomcat

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Why use a 1:7 twist when the only ammo it shoots well is the expensive 77 grain when a 1:9 twist will shoot just about anything from 55 - 69 grain pretty good?

I dont understand what the appeal of a 1:7 twist is when it limits you to the most expensive ammo, and shoots everything else crappy.

A 1:9 twist shoots pretty much anything pretty good.

I am serious - has anyone else seen this happen?
 

ORD

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

Your assumptions about the 1:7 twist barrels ONLY shooting 77gr ammo well and everything else "crappy" are completely unfounded from my experience. Same is true with 1:9 twist barrels shooting "pretty much anything pretty good." Most 1:9 twist barrels I have used won't shoot 69gr and heavier bullets as well as a tighter twist barrel. Now, not all 1:9 barrels are created equal and some will work well with heavier bullets, but not all.

I have numerous quality AR-15 barrels in varying lengths from 16" to 24" with 1:7 and 1:7.7 twists and while they do love the 77gr and 80gr pills a WHOLE LOT...they will each shoot 55gr ammo perfectly well. I sometimes shoot 55gr just for cheap practice ammo and it will shoot sub-MOA out of every 1:7 barrel I own.

Now, if you are comparing 77gr factory ammo (all match quality obviously) with 55gr Wolf or similar "crappy" ammo, then I agree with you on the accuracy problems...but those are directly related to the ammo and have nothing to do with the barrel twist.
 

3PER

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">Why use a 1:7 twist when the only ammo it shoots well is the expensive 77 grain when a 1:9 twist will shoot just about anything from 55 - 69 grain pretty good?

I dont understand what the appeal of a 1:7 twist is when it limits you to the most expensive ammo, and shoots everything else crappy.

A 1:9 twist shoots pretty much anything pretty good.

I am serious - has anyone else seen this happen? </div></div>


Where did you get the idea that a 1:7 twist cant shoot the lower weight bullets well? I have shot as low as 50 grain ammo in my DD M4 with excellent results.
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

From actual testing with Black Hills ammo.

I move the same Nightforce Optic from rifle to rifle,

I have two Noveske's and two RRA's - generally speaking the RRAS's shoot better at one-third the cost.
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I mean they shoot a wider range of ammo. With a 1:9 twist I am not limited to the heavy bullets - the 1:9 will shoot heavy stuff too, while the 1:7 twists wont.

Has anybody empirically tested their rifles?
 

cj1026

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I actually wanted to test differant rounds in my 16" 1:7.
Got to the range yesterdat. I shot Remington 45gr and 50gr HP, Hornady 55gr FMJ training ammo and some handloads of Sierra 65gr SBT, 69gr and 77gr HPBT.
As expected the the 65, 69 and 77gr rounds were awesome. 5 shot groups all round touching and all sub MOA.
As for the 45, 50 and 55. I was really suprised. The 55gr did not group very well. Maybe 1.5 to 2" at 100 yards. The 45gr was just under an inch and the 50gr was just over an inch. Kinda suprised me. Wasn't expecting them to shoot so good. But I'm happy they did.
Also with the 45, 50 and 55gr it was very easy to hit a 12" steel circle at 325 yards.
 

Prairie Dog Dundee

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

The only bullets the 1 in 7 won't shoot well are the thin skinned varmint bullets. The twist rate causes some like the Speer TNT and Hornady SX bullets to come apart in flight. I own nine 223 caliber rifles ranging from 1 in 12 to 1 in 7. One of the most accurate factory loads in all these rifles is the American Eagle 50 grain flat base hollow point. My heavy barreled bolt rifles, (Savage 1:9, Winchester 1:12 and CZ 1:9) all shot this load sub moa as does my RRA Varmint (1:8). My M4 and A4 Colts (1:7) shoot this load at just over 1 moa with a good scope mounted.

Your assumption of 1 in 7 rifles doing poorly with lighter bullets is incorrect.
 

LostSol

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I have shot everything from 45-77 gr in my LMT 16in 1/7 twist. I have never had an accuracy issue.
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I have a Noveske Recon stainless 16", 1:7 twist.
Shooting Black Hills (BH) 77 grain was 1.3 MOA
Shooting BH 55 grain was ~2 MOA

My Noveske Light (M249 barrel w 1:7 twist) was slightly larger MOA.

My LWRCI M6A3 1:7 shooting 55 grain BH was 3-4 MOA

My Rock River Chrome Moly was about 1 MOA w Black Hill 55 Gr.

This was all with the same Nightforce scope.


** This week I am taking 7 rifles to the range to run comparative tests:
The test is 4 five round groups shot with 55 and 77 grain Black hills at 100 yds.
I will use the same scope on each.

The rifles are:
Noveske Recon 16" 1:7
Noveske Light 16" 1:7
RRA 16" 1:9 - chrome moly
RRA 16: 1:9 - chrome moly - different rifle than above
RRA 16" 1:9 - chrome Lined
RRA 16" 1:8 - Stainless
LWRC M6A3 16" 1:7

I will post results.







I can shoot sub MOA with my REPR and M700.
 

kilo7788

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

Military M16A2 (20 in) and M4(14.5 in) are 1 in 7 and the standard ammo is a 62gr M855 and 55 gr M193.
 

sobrbiker883

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

1:8 is the most accurate for the broadest range of projectile lengths in my experience.

1:7 is what every mfr uses now because of the propensity for most of those that don't know better to buy what Uncle Sugar uses when it comes to evil black rifles.
1:7 is not used by .mil because it is the optimal twist for M855 projectiles, and 1:12 will do M193 just fine- 1:7 is .mils choice because it is necessary for stabilizing the length of the M856 tracer round.

1:7.7 or 1:8 is what wins most XTC and LR and F-Class with the .224 bullets.
 

eli polite

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

i have a walther 20" 1:8 and i have not been able to take the time yet to put different ammo through it.there are so many different kinds of ammo out there for this thing i was wondering if any one could hep me narrow it down before i hit the range.

in my stock pile i have roughly 10 brands in all different grain's

the barrel i have has polygonal rifling how much does the rifling play into the accuracy of the barrel.
 

Dtarget

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I bought my 1:7 so I can shoot HP @ 600. 1:7 shoots 55 gr just fine and I use it for 100 and 200 yard practice. I rarely see a 1:9 on the 600 yard line.
 

kraigWY

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Why use a 1:7 twist when the only ammo it shoots well is the expensive 77 grain when a 1:9 twist will shoot just about anything from 55 - 69 grain pretty good?</div></div>

Because I'm a high power shooter and at HP matches I only shoot 77 & 80 SMKs.

But, I do a lot of 100 yard reduced practice with 52 grn match bullets and they shoot excellant out of my 1 - 7 WOA upper.

This is from an army test, its a pretty good example and explains it better then I can.

Twist%20compairson.jpg
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

In my humble opinion, I suspect there is alot of myth and misconception regard the prevalent barrel twist preference for 1:7.

I plan on doing as empirical experiment as I can on Thursday this week.

In the preliminary testing I have done so far, this is what I've seen trending:
1:7 does not perform on 55 grain bullets as well as 1:8 or 1:9.

1:8 and 1:9 perform well across most weights including the following I have tried:
55, 62, 69, and 77

1:7 performs well on 77, but on lighter weights performance falls off.

(55 and 77 grain bullets tested are Black Hill red box)

More to come.
 

eli polite

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

ok i don't mean to be a nascence but i am new to the AR thing for as long as i can remember i have been a bolt guy the first time i shot one i was 8. so the AR i have is completely new to me and i am still learning and the most confusing thing about them is the barrel's i went with the 1:8 twist chromally with polygonal rifling and so far even with cheep ammo it doe very well.
so her is what i am getting at with all of the options out there what is the best all around barrel.. and i know that some of it is personal preference

choices:

stainless steel
chromally
chrome lined
standard non lined

conventional rifling
5 grove rifling
6 grove rifling
polygonal

cambering
.223
5.56
Wylde

add the 100's of different rounds for it

I'm sure there re a few more options add length's to that and it gets a little confusing maybe that's why i have been primarily a bolt guy i know there are a lot of options for that as well but whats well proven is easier to find
 

scotharr

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

As stated, the 1:9 twist is too slow for the heavier bullets: 69gr and up...depending. The actual results depends on temperature elevation, bullet length, muzzle velocity.

Most agree that you cannot "over-stabilize a bullet with a "too-fast" twist. Experienced shooters I know say error on the side of a faster twist because it doesn't hurt and sure can help. For example, you might find that your 1:9 twist shoots 77gr SMK just fine. But on a cold day at sea level, you might find it absolutely sucks and accuracy is lost. Error on the faster side I say. I use a 1:8 which shoots 77gr and less very well. Might want a 1:7.7 for 80gr and 1:7 for 90 gr bullets.
 

Dtarget

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

Thanks for doing some real world testing. What range are you testing at? I am interested how your results would change as you go to longer distances.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">
I plan on doing as empirical experiment as I can on Thursday this week.

</div></div>
 

CL1KKL4C

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I shoot m193 out of my 1/7 20" with more than satisfactory results. I never intended for my AR to be a precision rifle when I built it so 1-2" @ 100 is great to me.
 

adm845

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

Intersting to note: I load with sierra matchking 77gr bthps in my 1:7. On the box it says only for use in 1:7 barrels. The 1:8 and 1:9 dont spin the heavier bullets fast enough. If you want to shoot wolf and other crap then stick with the 1:9, but if you want to be able to shoot good competition rounds safely and accurately, get the 1:7.
 

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

We had 118 8 twist 5R barrels with Wylde chambers come in around Jan. They will not shoot any factory 55gr worth anything 1.5-2" at 100 but they will shoot 69s loaded with 24gr of RE15 OAL of 2.285 into 1/2" and some less. the 77s shoot almost as tight but I haven't had as much time to work a load for the 77, I have been shooting the 69 load for years. I can get 55s to shoot by handloading them with Benchmark and to a longer OAL. I use PRI mags so no problem with 2.285 OALs. IMO most factory 55gr FMJs just don't shoot well and can't be compared to match bullets or loads. ETA- I don't think you can place all barrels in the same grade by twist alone, some barrels on the market really are junk regardless of twist, others decent and some very good. The one thing I can say is that load of RE15 and 69s has shot very well in every barrel I have owned or tested in the last 15 years, if the barrel doesn't shoot that load I would take a good close look at the crown or have it checked for straightness, some barrel bores look like a banana when spun on a lathe.
 

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

Is anybody shooting any 52gr pills out of a 1:8? Looking to purchase a new upper and want to spit out some 52's-69's. Or what is the best twist for that range. Maybe there isn't.
 

TresMon

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists



I have a seven twist too, but don't forget a tighter twist cost's you velocity as well..
 

marduk185

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

not to hijack but related question here is how does one "optimize" performance of a 1 in 9 twist ar if thats all that is available and you wish to enhance for distance. what load? 69grain smk?
 

NoveSPR

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

my 1 in 7 launches 50 gr back hills match w/ excellent performance to 200 yds. and 77gr smk to 500 with equally good results.
 

SFC Carpentier jr

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

This is a very good topic on the AR barrel and what twist works with what bullet. I myself own quite a few AR's. I have one ar barrel that is in 1 X 12, a few with 1 X 8 twist barrel (this is the twist I have the most of), also have a few 1 X 9 and also one 1 X 7. As people have posted, not all barrels are the same. In the rifles that I have I found that in the 1 X 8 twist it will shoot bullets as light as 52 grns very well. Now will all barrels that have that twist do the same? You would have to see for yourself.

I have also shot 77 grn bullets in my 1 X 9 twist barrels.

Again you would have to test your barrels with different weight bullets. Of course you would think that with the faster twist barrels that it would not shoot the lighter bullets well.
 

Wild_Bill

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">In my humble opinion, I suspect there is alot of myth and misconception regard the prevalent barrel twist preference for 1:7.

I plan on doing as empirical experiment as I can on Thursday this week.

In the preliminary testing I have done so far, this is what I've seen trending:
1:7 does not perform on 55 grain bullets as well as 1:8 or 1:9.

1:8 and 1:9 perform well across most weights including the following I have tried:
55, 62, 69, and 77

1:7 performs well on 77, but on lighter weights performance falls off.

(55 and 77 grain bullets tested are Black Hill red box)

More to come.

</div></div>

I would try a diferent brand of 55gr projectile i expect a diferent 55gr projectile will shoot better it all will come down to your projectile. i have shot 50 to 9-gr projectiles through a 30" 6.8 twist all under MOA projectile breand were Hornady, Sierra, Nosler and Speer. they all worked very well the 69gr projectiles shot aswell as the 80's and 90's with 5 shot groups under 1/4moa at 300 yards.
 

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">1:8 is the most accurate for the broadest range of projectile lengths in my experience.<--i found this very true you shoot more different ammo !

1:7 is what every mfr uses now because of the propensity for most of those that don't know better to buy what Uncle Sugar uses when it comes to evil black rifles.
1:7 is not used by .mil because it is the optimal twist for M855 projectiles, and 1:12 will do M193 just fine- 1:7 is .mils choice because it is necessary for stabilizing the length of the M856 tracer round.

1:7.7 or 1:8 is what wins most XTC and LR and F-Class with the .224 bullets.

</div></div>
 

splean

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: marduk185</div><div class="ubbcode-body">not to hijack but related question here is how does one "optimize" performance of a 1 in 9 twist ar if thats all that is available and you wish to enhance for distance. what load? 69grain smk?</div></div>

I have a 20" 1:9 barrel and I had some great results with 52gr and 69gr handloads. One group of 52gr was a little less than .5 MOA.
 

Sterling Shooter

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Why use a 1:7 twist when the only ammo it shoots well is the expensive 77 grain when a 1:9 twist will shoot just about anything from 55 - 69 grain pretty good?</div></div>

Because I'm a high power shooter and at HP matches I only shoot 77 & 80 SMKs.

But, I do a lot of 100 yard reduced practice with 52 grn match bullets and they shoot excellant out of my 1 - 7 WOA upper.

This is from an army test, its a pretty good example and explains it better then I can.

Twist%20compairson.jpg



</div></div>

I've had the same sort of experience that Kraig has had. Using a 1/7 twist, I shoot 53 grain flat base bullets for 100 yard reduced, 77 grain bullets for 200 and 300 yards, and 80's for 500, 600 and LR.

At 100, accuracy testing reveals I can expect, with either 53's or 80 grain bullets, groups in the arena of 3/4 minute for a 20 round string of fire-iron sights, prone with sling.

There are so many factors to all of this accuracy stuff; but, regarding barrel twist, I think, why not make em all 1/7. I think, for most, the 77 grain bullet is appropriate for everything; plus, with the 1/7 the shooter can get a bullet to some pretty insane distances nose-on.
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

As promised I went to the range today and test 5 AR's with twist rates of 1:7, 1:8, and 1:9.

All tested with the same ammo and scope.
Black Hills 68 BTHP, Atlanta Arms & Ammo Match 77 BTHP, 55 Grain reloads, Federal 55 grain, SS109 Green Tips 62 grain.

Rifles tested:
Rock River 16" Stainless 1:8
Rock River 16" Chrome Moly 1:9
Rock River 16" Chrome Lined 1:9
Noveske Recon 16" 1:7
Noveske 14.5" M249 barrel 1:7


I dont have the results compiled coherently yet I will post the data but.....

The Rock Rivers were clear winners in outshooting the Noveskes.

The Chrome Moly and Stainless shot tighter groups using all ammo tested.

The 14.5 Noveske was the worst performer.

The RR's seemed to like the 68 grain bullets best shooting about 1.25 MOA on average.

I have a LWRCI M6A3 to shoot and test. I sent the LWRCI back to the manufacturer because it was shoot 55ing grain BH ammo at about 5-7 MOA. I have yet to talk with their cust service to determine what their finding are. But they did tell me their accuracy standard was 2 MOA at 100 yds.

I will retest all guns with Black Hills 55 Match and Black Hills 77 Match next week. I will post MOA data over the weekend.


 

Quick Karl

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<span style="color: #000099">My 7-twist seems to like 77g bullets AND 52g bullets... I will get some targets for the 52g bullets scanned and add them to thispost tomorrow. It will shoot 52g Berger Match into .5 MOA all day long.</span>

SPR0109-06-08.jpg

09SEP2008BESTSMALL.jpg

 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

QuickKarl -

It looks like you have a specialized gun custom built with handloads.

I am using production guns with factory ammo. But I am interested in the viability of twist rates.
I am coming to a conclusion that 1:7 is good primarily for guys like you - with highly specialized rifles. For guys like me, with production stuff, 1:8 to 1:9 is a better choice.
I was talking with an old timer at the range this week, and he uses 85 grain bullets out of his 1:7.

I am looking for a good all around plinker, range rifle, competition rifle, and zombie hunter.
1:8 seem like the twist to to with.


I am heading off to the range this morning to shoot the Noveske Recon with 55 and 77 grain Black Hills.
 

Kapac

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

As it has been stated, there are so many varibles to deal with when talking accuracy and factory ammo. Here are just a few things to consider.

The biggest thing is freebore (bullet jump) and how tight the tolerences of the chamber. From company to company not only do they chamber with different techniques but also when dialing in the barrel they have different peramiters to hold (a given range of run out).

Hence higher priced barrels and less expensive barrels.

Another major factor is how good the barrel is. Some will take longer to break in and some will need to be lapped to get them to shoot better. Then some just dont ever improve.

Its basically the same as shooting a 22lr, you can go thru many different brands and weights before you find the one that works best in that barrel and what ever that may be is as good as it gets.

Kapac
 

Quick Karl

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<span style="color: #000099">Follow up as promised:

IMHO, I'd go for the 7-twist because, in my experience, it doesn't degrade the accuracy potential of the lighter bullets, and you would always have the option of dropping some heavy pills into tiny little circles at much greater ranges...

This is XM193 55g FMJ surplus at 100 yards (good enough for me for box ammo):
77150a8a.jpg


This is 77g Sierra MatchKings loaded to magazine length and fired from a bench with no extraordinary effort:
29b81fc2.jpg


Some more 77g with a different powder:
b78b6fd5.jpg


And these are 52g Bergers:
8abc60f4.jpg
</span>
 

Sterling Shooter

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I suspect research would reveal the superiority of the 1/7 over others. It appears it will get a higher B.C. bullet to a greater distance nose-on than is possible from a slower twist. That means more accuracy at distance. The heavier bullets also take less wind favor for a good hit at distance; and, the heavier bullets seem to be as concentric as alternatives, so, they are as likely as others to always go in the direction the barrel is pointed. I'd like to see Blackhills make a commercial equivalent of the Mk. 262 load. It's as versatile as the AR is.

Thinking about it, why even consider a slower twist. Although it assures results from lite bullets the slow twist is still for the most part useless, considering the applications generally suited to the AR genre. The heavy bullets look to be more ideal for any imagined scenario.
 

Tomcat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I like 55's because I can get them alot less expensive that others.

Beside, my AR's all shoot heavier bullets better, I admit it. - all twists. Though, the performance falls off with fast twists and light bullets worse than slow twists with light bullets.

I dont want to be tied to BH 77's at 50.00 / box, when I can get 55's for less than half that.

But, expecting 1 - 1.5 MOA from a production gun with production ammo is seeming to be a tall order. Especially when you start talking about light bullets.

I imagine there are some AR's that can do it, and if you are lucky enough to have a 1 MOA PRODUCTION AR, then go buy a lottery ticket.

Karl - you've got a great shooter there, but its anything but production gun and ammo. But, I understand the point you make that fast twists CAN shoot light bullets.
I understand that heavier bullets are more stable than light bullets, and that a faster twist stabilizes them better.

My problem is that I am not seeing 1 MOA performace with 1:7 twists and 55's with production level guns and ammo.



 

jp_colt

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

I have shot from 62 to 80 in my 1:7 with no issues. where as 69 is pushing it for the 1:9. I go for the 77 to 80 any day
 

Sterling Shooter

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">I like 55's because I can get them alot less expensive that others.

Beside, my AR's all shoot heavier bullets better, I admit it. - all twists. Though, the performance falls off with fast twists and light bullets worse than slow twists with light bullets.

I dont want to be tied to BH 77's at 50.00 / box, when I can get 55's for less than half that.

But, expecting 1 - 1.5 MOA from a production gun with production ammo is seeming to be a tall order. Especially when you start talking about light bullets.

I imagine there are some AR's that can do it, and if you are lucky enough to have a 1 MOA PRODUCTION AR, then go buy a lottery ticket.

Karl - you've got a great shooter there, but its anything but production gun and ammo. But, I understand the point you make that fast twists CAN shoot light bullets.
I understand that heavier bullets are more stable than light bullets, and that a faster twist stabilizes them better.

My problem is that I am not seeing 1 MOA performace with 1:7 twists and 55's with production level guns and ammo.



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You seem to be creating a problem for yourself with preferences that defy reality, as well as what would get the best results. If the expense of bullets is paramount over performance-get another hobby. Also, the reason you're not seeing the performance you desire is more about knowing how to shoot than anything about the gun or ammunition. Executing the firing task is not all that there is to it. I don't mean to be doggin' ya; but, just think about what you're saying, you're creating rules for yourself for the sake of what, a handicap. After all, lite bullets and slow twists are certain to produce a handicap-while perhaps producing needless accuracy on any practical target, the experience is limited to a short distance. This undermines the versatility of the firearm for most stuff you'd want, including MR and LR possibilities.
 

maladat

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Re: AR: 1:7 or 1:8 or 1:9 barrel twists

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">But, expecting 1 - 1.5 MOA from a production gun with production ammo is seeming to be a tall order. Especially when you start talking about light bullets.</div></div>

Just came across this thread so I thought I'd toss in my experience.

I built my own AR on a Vltor MUR upper and a Noveske Recce 16.1" 1-7" twist stainless barrel. It is basically the same as the production upper Noveske sells (also used a Noveske low-profile gas block) except I have a different FF rail (DD Lite Rail 12.0) and muzzle device (PWS FSC556). Using a TA01 ACOG and PRVI Partisan 75gr match ammunition (~$500/1000 rounds, I paid $440 but I'm not seeing it for that now) I can shoot 1.5 MOA 10-shot groups pretty easily. I haven't shot any other ammo at all out the gun, though.