Is a 1:7 twist too much for 55g .233 ammo?

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Tikka223

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Folks I am flip-flopping as I shop for a rifle and it's between Tikka and Savage.

I love the smooth action on the T3s and am seriously thinking about getting the T3 Varmint in .233 and it has a 1:8 twist. Triggers are crisp and from reading reviews they are plenty accurate. Only problem is that I'm afraid it'll be more costly to modify (ie barrel change or stock change).

Before I was looking at the Savage Model 10s (Hunter Max / PC). Now I'm looking at the 12 VLP, I find the stainless Savage actions are much smoother than the blued actions. Also, I like the idea of being able to sand a stock down for a better custom fit. The big question: is the 1:7 twist going to be too much for the lighter 55g bullets?

Thoughts?
 
I don't think you can really " over stabilize" a bullet

I think the bigger issue is that you will have to change your name from Tikka223 to Savage223.
 
Shooting 55gr. bullets pretty much defeats the purpose of having a fast twist barrel.
High quality 55s will shoot well in a quick twist. Lower grade bullets may not.
But yes, you can shoot 55gr. ball through a quick twist barrel.
 
it depends on the rifle- our friend,'mike dillon, did an article in the blue press years ago where he took a 1/12 m16 shooting and a 1/7 m16a2 both shooting the 55 grain , and he found that the best he could do with the 1/7 was 6 inch groups- but the 1/12 would shoot 2 inches and sub down to 1 inch- when he switched to 69 grain, the situation reversed- these were the then standard 20 inch barrels
 
I shoot lots(but not enough) 55 gr factory ammo out of my 7.7 twist AR15. They work just fine.

The shooting I do is mostly between 1, and 500m, and the 55gr I use is all FMJ. AE, winchester, remington UMC, etc.

I don't have any evidence of keyholing.
 
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Short 223 rifle twist history

Sorry for the long post but the complete answer is long!

History of 223 barrel twist
-------------------------
Early AR15 had 1-14" for both accuracy and lethality but it was found to be insufficient to properly stabilize to bullet.
The twist was then changed to 1-12" which is optimal if you plan only on shooting 55gr FMJ M193.

When NATO adopted SS109 63gr bullet a faster twist was needed to stabilize this bullet and the corresponding tracer bullet. Because of this, a 1-7" twist was standardized.

Civilian shooter wanted to be able to shoot both 55gr M193 and 63gr SS109 ammo when for the compromise 1-9" which works very well from 40gr up to 69gr HPBT.

The fast 1-7 twist can stabilize magazine fed 77gr HPBT and up to 90gr hand fed cartridges.

What it means--------------
1-12" is best for 55gr FMJ
1-9" is good up to 69 HPBT (SMK)
1-8" is good up to 75 HPBT (AMAX)
1-7" is good up to mag fed 77 HPBT (SMK) or hand fed 90gr HPBT

About bullet stability: a bullet to be stable must have a stability factor of 1.3 - 1.4 or more but you will run into problems when the stability factor reaches 3.0 if the bullet is not of high quality (it spins so fast that any imperfection my destroy any accuracy).

The problem is that cheap 55 FMJBT have a large stability factor for 1-7" barrel twist therefore will shoot inaccurately and might even keyhole.
If you use match bullets there should be no issue if the stability factory is around 3 (I don't want to calculate this, just use JBM calculator).

1-7" works with high quality (read match) 55gr bullets

Again, sorry for the long post,

Alex
 
Nothing wrong with the long post, the more information the better. All the other forums I've been reading up on a filled with guys going on about how they can't see a difference using ARs at 50-100 meters. I plan on shooting farther than this.

Right now I shoot Federal 55g boat-tail FMJs and just picked up some Hornady 55g V-max but haven't had the chance to try them yet. Would these fall into the category of "high quality"?

The biggest problem for me is the lack of selection in my neck of the woods, being picky on ammo isn't always possible ... but then again at some point down the road I'll start reloading.
 
Tikka223 said:
Nothing wrong with the long post, the more information the better. All the other forums I've been reading up on a filled with guys going on about how they can't see a difference using ARs at 50-100 meters. I plan on shooting farther than this.

Right now I shoot Federal 55g boat-tail FMJs and just picked up some Hornady 55g V-max but haven't had the chance to try them yet. Would these fall into the category of "high quality"?

The biggest problem for me is the lack of selection in my neck of the woods, being picky on ammo isn't always possible ... but then again at some point down the road I'll start reloading.
Click to expand...

High quality ammo is Hornady 60gr TAP-FDP (the 75gr is better for 1-8 and faster) and Federal Gold Match 69gr (77gr is better for 1-7" if you can find it).

If you shot MIL-spec ammo go for Winchester M193 and PMC mil-spec ammo.
The best MIL-SPEC ammo that I've recently shot is PMC M193. It gave my 1cmx1cm 5 shot groups from a semi at 50m indoor! I have not tried 63gr PMC SS109 ammo.

Use the heavier bullet if you have the twist to do so,

Alex
 
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The only benefit of the longer, heavier bullets in most cases is their ability to buck the wind a bit better - so you really only gain if you are shooting long distances (hunting applications aside of course).

The bigger issue is the comparison of a Tikka to a Savage. One is craptastic and one is Finnish...
If you want to modify your gun, go with a Remington - same craptastic quality as Savage but more aftermarket available to make it less craptastic.....;)
 
beltfed said:
The only benefit of the longer, heavier bullets in most cases is their ability to buck the wind a bit better - so you really only gain if you are shooting long distances (hunting applications aside of course).

The bigger issue is the comparison of a Tikka to a Savage. One is craptastic and one is Finnish...
If you want to modify your gun, go with a Remington - same craptastic quality as Savage but more aftermarket available to make it less craptastic.....;)
Click to expand...

What factory rifle are you shooting?:rolleyes:

To the OP-

1-9 works great with cheap 55gr stuff.
1-8 will work with 77gr SMKs (AR mag length reloads)

I have had both AR's and Boltguns in 1-9 and 1-8. Best groups in 223 were around .34moa on the AR and .32moa on the Bolt gun (need to set up a load for that) Both are out of sub 17" barrels (bolt and semi) This was with 77gr SMKs in 1-8 twist barrels

My Savage is anything but craptastic:kickInTheNuts:
 
I think you will be limited more by the fact that you are shooting factory ammo than by the fact that you are shooting light bullets in a fast twist barrel.
 
beltfed said:
Sako. I gave up on both Remington and Savage (700P an 12LVS) when I came to the realization they are crappy money pits.
Click to expand...

20 inch TRG is 10.25lbs. 20inch Remington LTR is 7.5. I'll lug the LTR around for the 3 lbs of fit and feel, and potential accuracy loss.

But yes, a Remintgon will take nearly the same $ and more dicking around then the commie rifle.
 
No ARs for me. Right now I'm shooting a T3 Lite, fairly accurately, but now it's time to upgrade and I'm considering my options. The 12 VLP comes with a 1:7 twist, the Tikka T3 Varmints have the 1:8 twist.
 
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