AR rifling twist, 1:9 or 1:12?

[1BadF350]

I know this has probably been discussed in detail but lets bring it up again for just a quick minute.
I'm looking at a RRA 24" Varmint. I have to choose between 1:9 or 1:12 twist. The gun will mostly be used as varmint/target out to 300 or so (may try the occational "hail mary shot". I know the faster twist is not recommended for light bullets. I'm afraid of getting the 1 in 9 because that will limit me to a heavier, slower bullet and I don't want to give up flat trajectory of the lighter bullets. The problem is that I don't want to regulate myself to the 1 in 12 and lose knockdown power of a heavier bullet.
Does this make any sense? Is my logic all wrong?
The main question is whether there is a happy medium? At what bullet weight will the 1:9 twist not be good. Would it tear apart frangible bullets? Am I a pain in the a$$?

[Seraph]

My opinion is that the 1/9" twist will give you more versatility.

[FirstFreedom]

I'd say that it's called the varmint for a reason. It needs a 1 in 12 to work well with light varmint bullets (35-55 grains). If that's the use it's gonna be put to, then get 1 in 12. If, on the other hand, you have NO other rifles for SHTF, and this one is going to double in that theoretical role, then get the more versatile 1 in 9. OR, if you going to try your hand at extreme-range shooting at varmints (say, over 400 yards). Then, the 1 in 9, for the heavier bullets. But most people are going to have a very hard time hitting something small that far away, so it turns varminting from fun into work, but it's whatever floats your boat.

[1BadF350]

I assume I'll be shooting between 50-60 grain bullets.


This will just be a fun addition to my collection.

[Pthfndr]

If your choices are between 1/9 and 1/12 go with the 1/9. It will shoot the lightest bullets just fine. I shoot highpower and know lots of others who do the same and use the light bullets for reduced course matches out of barrles with 1/6.5 - 1/8 twists and never have problems with quality bullets blowing up in mid air.

[FirstFreedom]

ok, but define "light" bullets. What weight precisely are you talking? And not all light bullets are the same. Some are lightly constructed varmint bullets (will fly apart when spun too fast), and some are heavier all-purpose, match, or defensive bullets, which won't fly apart. Are you SURE the 1 in 9 WON'T 'splatter' a 40 gr hornady v-max or similar? I would think that it would.

In other words, the hi-power shooters you know who shoot 'light bullets' fine from 1 in 9 or 1 in 6.5 for short courses, as you say, exactly what bullets are they?

[Pthfndr]

In other words, the hi-power shooters you know who shoot 'light bullets' fine from 1 in 9 or 1 in 6.5 for short courses, as you say, exactly what bullets are they?

Everything from 45gr varmint bullets up to 52gr matchkings. A 1/9 twist will NOT blow up even 40gr bullets, and will allow you to shoot bullets up to the 75gr. The 1/12 normally will not stabilize bullets heavier than 55gr reliably.

[FirstFreedom]

Hmm, ok, well there you have it. I was incorrect, looks like. Get the 1 in 9!

[1BadF350]

I was worried about the frangible ammo coming apart, but I guess it wont?

[kirbymagnum]

Do you guys think a 1-8 twist can handle 45 grain bullets?

[joshua]

I have the 1x7 twist AR barrel and it wont shoot 55 grain and below weight bullets worth for crap. The 62 grain military green tip rounds are fine, but it really needs 69 grain to shoot well. The 77 grain Sierras pushed at primer flattening velocities will do .3 moa. Remember that the .224 is still a small diameter round and if you increase the bullet weight by 10 grains it will start adding length faster than the bigger caliber bullets. I tend to look at 1x9 as the happy medium, but with such a wide variety of .224 bullets you will need at least 2 barrel twist/uppers to take advantage of the light - heavy and everything in between. The accuracy will speak for itself. josh

[FirstFreedom]

that brings up the issue that, just because it doesn't spin the light bullets apart doesn't necessarily mean it will shoot well with them.

[joneb]

+ one for 1:9