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Posted By: BriGuy 1:9 twist vs 1:10 - 09/15/13
In my new 30-06 I am going with a 1:9 twist just incase I need it to stabilize the longer heavy VLDs. I don't anticipate shooting anything lighter than 150 grains, and 168 grains VLDs will probably be a staple diet for my 06... I'll probably shoot 180 grains as well.. If I get the urge to stretch its legs 200 grains and up is the game.

I've always shot a 1:10 twist in a 06, and was wondering if 1:9 would really be to fast for lighter bullets or will I notice a significant difference one way or the other.

Thought I would get an opinion from those who have experience in this are. I have no idea why, but twist rate always concerns me somewhat because I've always been taught that lighter bullet accuracy suffers a bit if you spin a bullet faster than necessary to stabilize it in flight. Any thoughts to help clarify this from the more experienced shooters would be appreciative.
Posted By: rem06 Re: 1:9 twist vs 1:10 - 09/15/13
im shooting a 11tw in a 300 Norma with 210Amax,my speed is higher but it works well.

twist is based on bullet "length" not weight.It just happens that longer is usually heaviet.

you wont have any problems with 10tw as i shot 200SMK in a 30-06AI very well with an 11tw also.

http://bulletin.accurateshooter.com...t-rate-with-berger-stability-calculator/
Posted By: aalf Re: 1:9 twist vs 1:10 - 09/15/13
Originally Posted by BriGuy
I've always been taught that lighter bullet accuracy suffers a bit if you spin a bullet faster than necessary to stabilize it in flight.

That's true, but only valid if you and your equipment can shoot the difference.

A factory 700 heavy barreled 308 of mine with a 12 twist stabilized a 190 Match King just fine, so unless you were wanting to go to the real 30 cal heavyweights, a ten should be fine.
I don't shoot a .30-06 but do shoot a lot of .308Win and .300Win Mag for work. I shoot 175gr SMK from the 1-11 .308Win and 190gr SMK from 1-10 .300Win Mag. I have shot some 220gr SMK from the 1-10 as well with good results but the loads were too hot for the guns across the board. Long and short of the story, I know either twist will keep those bullets stable past 1300m. I don't think you will regret a 1-9 but it might not be necessary.
Posted By: jimdgc Re: 1:9 twist vs 1:10 - 09/15/13
Take a look at Berger's website. No need to go to a 1:9. A 1:11 will actually stabilize about any hunting bullet.you would want to shoot. I shoot 190 gr and 208 gr Hornady bullets out of a M70 with 1:11 twist.
Posted By: rem06 Re: 1:9 twist vs 1:10 - 09/15/13
wow, did some more calculating and lots of good replies

ran a 240SMK at 2500fps in a 10tw and got 1.55 stability factor.
there is absolutely no need to go 9tw.

you can over spin but you want to have the best stability for what you're shooting under the worst conditions(temperature/elevation). Run a few bullets in the formula.

Posted By: BriGuy Re: 1:9 twist vs 1:10 - 09/15/13
Berger website shows a 168 grain VLD using a 1:13 twist or faster G1 BC being .473

I think 1:10 would have been fine for Bergers I would check out 165 SGK but can't find any information on their website for recommended twist rate. Never shot the VLDs but the SGK were wonderful performers on deer for me..
Posted By: MontanaMarine Re: 1:9 twist vs 1:10 - 09/15/13
I shoot 208s all the time in a 1/12 308Win, and have had good sub-moa accuracy with the Hornady 225gr BTHP at 1/12, 2500 fps as well.

In my 1/10 30-06 I've gone up to the 240gr SMK with excellent accuracy past 1000 yards.

The only place I can see where 1/9 might benefit is if you should ever wish to load heavies at subsonic velocities.
Posted By: BriGuy Re: 1:9 twist vs 1:10 - 09/15/13
1:11 may not be a bad option in a 30-06 with a bullet weight in 150 - 180 grain range for whitetails which this rifle is intended for.

I may load up 200+ grains, but it won't be out of necessity. I believe 1:11 twist would handle some of the bigger bullets just fine...
Posted By: rem06 Re: 1:9 twist vs 1:10 - 09/15/13
Quote
1:11 may not be a bad option in a 30-06 with a bullet weight in 150 - 180 grain range for whitetails which this rifle is intended for.

I may load up 200+ grains, but it won't be out of necessity. I believe 1:11 twist would handle some of the bigger bullets just fine...


there ya go! 10 is plenty fast enough and 11 will be just fine and you wont have to worry about over spinning the light weights!
9tw..???? NAH...wrong way

Posted By: ADR17 Re: 1:9 twist vs 1:10 - 09/28/13
1-10 is fine 300 win mags shoot 230 grain at 1-10 at 190 you will be good with 1-10
Posted By: BobinNH Re: 1:9 twist vs 1:10 - 09/28/13
I've had 1-9 twist 300 Winchester and Weatherby mags....if I were a mono shooter, I'd get a 9 twist in 30/06 in a heart beat.
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