As a avid hunter and die-hard bolt action rifle guy who insists on sub-MOA accruacy from all my hunting rifles, I find myself in a bit of a quandry. I'm absolutely hooked on IDPA pistol competition and am now contemplating giving 3-gun competition a try (rifle, shotgun and pistol) a try. As such I've decided that I'd like to build an AR-15 rifle, but want to have better accuracy than the standard AR. (within reasonable investment levels)

It seems like I learned at one time that the little/light .22 bullets are significantly impacted by changes in rate of twist. AR barrel makers offer 1:8, 1:9, 1:10, 1:12 and 1:14 inches, in heavy stainless, fluted, etc.

Knowing that I'd use it for 3-Gun as well as varmits at the outer reaches of the .223, what would you folks, the knowledgable members of this very learned institution, recommend to me as far as rate of twist? - EB

It depends on your bullet. I have a Magnum Research Mountain Eagle in .223 and it has a 1 in 14 twist and I can not shoot anything over 52 grain. Shilen has a table that lists bullet with twist for calibers.

I would recommend picking the rate of twist based on the heaviest bullet you intend to shoot. For instance, if you will shoot nothing heavier than 55 grain, then I have found, 14 twist to be ideal. 12 twist up to 63 gr., 9 twist up to 70 gr., and anything heavier than 70 gr., 8 twist.

I just finished a custom .223 using a Shilen, 14 twist barrel which just loves 55 grain bullets. Maybe you got a bad one Chic. FWIW, that Hornady 52 gr. hollow point is about the most accurate bullet I have ever fired in a .223...

Westpac, wouldn't surprise me, I got it from Howard.

However, it has a Krieger barrel and shoots 52 grain bullets into little bug holes, so I am not complaining.

I got hung up on twist in .223s awhile back. After trying a number of different twists with bullets no heavier than 55 grains, I settled on the 1-12" twist. It shoots the 40 grainers as well as a 1-14" plus allows the 55 grs to be used effectively.

They also make the 223 in a 1:7 1/2 twist.there has been so much written about barrel twist in the 223 cal since the govt do so many experiments and changes.And before,nobody gave a good god dam what the twist was. Now everbody puts in granite on what twist will shoot what bullet. This is also has so much on the bullet lenght and design. ect,ect,ect. I better tell TWO 223,s that. Both of them have a 1:12 twist and the three most accurate bullet i shoot are a 50gr,55gr, and how about this one,a 70gr. The 70 grain is what i have used to kill many hogs,deer,and other animals. I guess the barrel doesn,t know its suppose to shoot 70gr bullets. ACCORDING to all the experts! vangunsmith

1/9 the heaviest you should go is 68-69gr. This isn't an absolute. Some 1/9 barrels will shoot heavier bullets. Some won't.

1/7 works well for weights from 55gr to at least 77gr. 77gr is the heaviest I've shot so far in my AR.
My AR has a 1/7 barrel.

Weights under 55gr aren't recommended in 1/7 barrels due to over stabilization. I can't comment directly about this issue. Maybe someone else can.

Good luck in three gun. I'm thinking about three gun or the local practical rifle matches with my new AR.
That way I can suck at both handguns and long guns.

ZM

I do not shoot more than 55 grains in any of my 223 rifles and one of them is 1-14 and the rest atre 1-12.......all shoot quite well.
I wish the 1-14 was also a 1-12 but it's still out there killing prairie dogs

quote:

Originally posted by vapodog:
I do not shoot more than 55 grains in any of my 223 rifles and one of them is 1-14 and the rest atre 1-12.......all shoot quite well.
I wish the 1-14 was also a 1-12 but it's still out there killing prairie dogs

Just curious, if you are not shooting anything heavier than 55 grain bullets, and the 14 and 12's all shoot quite well, why do you wish the 14 were a 12?

Malm,
my experience with the match shooters has been that the 14 twist is marginal for 55 grs.

Traditionally a 1-12 was considered enough for bullets up to 60 gr. This is not quite so with todays bullets. The plastic tips and long boattails used today result in a longer bullet which requires more twist. Also, "overstabilizing" is not nearly the sin that it used to be due to the much better quality bullets that are available today. We use a lot of 1-7 twist barrels on both match guns and varmint guns, and they shoot just fine with the lighter bullets. If I were building a gun just for 45-55 gr bullets I would not choose a 1-7, but they will shoot them just fine.

Decide what will be the heaviest bullet you intend to shoot then get enough twist to handle it and don't worry about the lighter bullets.

John

twist rate is determined by bullet weight not caliber.

Buliwyf, it is determined by bullet length (usually measured in calibers), not weight. A solid copper of the same weight as lead needs a faster twist.

I like 1:7 in an AR so that I can shoot 77 grs and have a chance of hitting something at 1000 yards.

cmmg has nice 1 in 7 bbls I like the 1 in 7 best and now I know 500 gr and I agree on something wonder of wonders

I have ARs in 1 in 9"
I have a Ruger #1 in 1 in 12"
I have a Mauser with Douglas 1 in 16"

The 16" is best with 35 gr Vmax, but will not stabilize 55 gr Vmax.