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1x10 or 1x11.25 twist for 7.62?
- Thread starter DoubleBarrel
- Start date
Re: 1x10 or 1x11.25 twist for 7.62?
Depends on the bullet weight, design and bearing surface.
Back in the day, almost all 30 cals were 1 in 10, going back to the days of the Krag (220 gr RN) and 03' Springfield (172 gr boattail).
The notable exception was the Savage 99 in 300 Savage that was 1 in 11 as it was sold as "equalling" the 30-06 of those days with a 150 gr bullet at 2700. In my 300 Savages I use the 130 Barnes TSX which has the bearing surface of a conventional cup and core 150 gr. They shoot into 1" and kill medium game very dead. In my 16" TAC DPMS 308, which is I believe 1 in 10, I shoot all kinds of 150s and 165-8s with excellent results considering the light weight and only a 1-4 scope. Typical 5 shot groups with the Varget/CCI 250/168 A Max run about 1" and German Mil-Spec 147 gr ball does about 1.5". If you get an "entry gun" like my TAC, I doubt it would make a difference. If you are getting a heavy barrel 18" that you plan to shoot out to 500 or more, then you might want to use a 175 or maybe more. Conventional wisdom would say 1 in 10 but there seem to be some folks doing well with a slower twist DEPENDING on the bullet.
You might want to look at Berger's chart on the 308 (which applies to their bullets)
http://www.bergerbullets.com/Cartridges/30%20Cal/308%20Win/308%20Win.html
Remembering that a Berger 180 VLD is miles away from Sierra flat base 180 Gameking.
Lots of quacking to say "it depends".
good shooting!
My TAC:
Depends on the bullet weight, design and bearing surface.
Back in the day, almost all 30 cals were 1 in 10, going back to the days of the Krag (220 gr RN) and 03' Springfield (172 gr boattail).
The notable exception was the Savage 99 in 300 Savage that was 1 in 11 as it was sold as "equalling" the 30-06 of those days with a 150 gr bullet at 2700. In my 300 Savages I use the 130 Barnes TSX which has the bearing surface of a conventional cup and core 150 gr. They shoot into 1" and kill medium game very dead. In my 16" TAC DPMS 308, which is I believe 1 in 10, I shoot all kinds of 150s and 165-8s with excellent results considering the light weight and only a 1-4 scope. Typical 5 shot groups with the Varget/CCI 250/168 A Max run about 1" and German Mil-Spec 147 gr ball does about 1.5". If you get an "entry gun" like my TAC, I doubt it would make a difference. If you are getting a heavy barrel 18" that you plan to shoot out to 500 or more, then you might want to use a 175 or maybe more. Conventional wisdom would say 1 in 10 but there seem to be some folks doing well with a slower twist DEPENDING on the bullet.
You might want to look at Berger's chart on the 308 (which applies to their bullets)
http://www.bergerbullets.com/Cartridges/30%20Cal/308%20Win/308%20Win.html
Remembering that a Berger 180 VLD is miles away from Sierra flat base 180 Gameking.
Lots of quacking to say "it depends".
good shooting!
My TAC:
Re: 1x10 or 1x11.25 twist for 7.62?
Dont think you'd find a WHOLE lot of dif. between those two twists if you were going to shoot differing bullets. The 10 would lean towards those with more bearing surface (usually the heavier), the 11.25 would lean towards those with less bearing surface ( usually the lighter bullets). The exception to the weight rule is some of the bullets designs these days give a very long bearing surface to the lighter bullets too, such as these new 155's like Scenars and Amax's. The 11.25 twist on my AR10T will shoot everything from 147gr to 178's well but it prefers the 178 Amax's.
okie
Dont think you'd find a WHOLE lot of dif. between those two twists if you were going to shoot differing bullets. The 10 would lean towards those with more bearing surface (usually the heavier), the 11.25 would lean towards those with less bearing surface ( usually the lighter bullets). The exception to the weight rule is some of the bullets designs these days give a very long bearing surface to the lighter bullets too, such as these new 155's like Scenars and Amax's. The 11.25 twist on my AR10T will shoot everything from 147gr to 178's well but it prefers the 178 Amax's.
okie
Re: 1x10 or 1x11.25 twist for 7.62?
i have ordered a Krieger 1/11.25 on my 308win ... it's ok for bullets from 168 to 190 grs.... 1/10 is for 300 wm or 338 Lm
i have ordered a Krieger 1/11.25 on my 308win ... it's ok for bullets from 168 to 190 grs.... 1/10 is for 300 wm or 338 Lm
Re: 1x10 or 1x11.25 twist for 7.62?
Get the 10 twist. You won't be shooting the heavier bullets in an AR10 without first modifying the gas system, but the faster twist will ensure better stability of the 168's and 175's if you want to shoot at ranges beyond 600 meters.
Get the 10 twist. You won't be shooting the heavier bullets in an AR10 without first modifying the gas system, but the faster twist will ensure better stability of the 168's and 175's if you want to shoot at ranges beyond 600 meters.
Re: 1x10 or 1x11.25 twist for 7.62?
Except w/ a few exceptions there is no 11.25 twist!!!! They were intenteded to be 1-11. Tooling slips and you get 11 and change!!! Like saying 10.25 or 12.25!
Except w/ a few exceptions there is no 11.25 twist!!!! They were intenteded to be 1-11. Tooling slips and you get 11 and change!!! Like saying 10.25 or 12.25!
Re: 1x10 or 1x11.25 twist for 7.62?
my dads ar10 has a krieger barrel and it is stamped 11.25 and it shoots everything from 175 to 147 with good results 1moa or better.
my dads ar10 has a krieger barrel and it is stamped 11.25 and it shoots everything from 175 to 147 with good results 1moa or better.
Re: 1x10 or 1x11.25 twist for 7.62?
consider the quality of bullet you are going to use. If you are gong to be shooting ball ammo or the equivalent 1-10 is going to spin them faster and exaggerate any imperfections. Is is said that you can't over spin a good bullet, but you sure can over spin a marginal or bad one.
Good luck
Jerry
consider the quality of bullet you are going to use. If you are gong to be shooting ball ammo or the equivalent 1-10 is going to spin them faster and exaggerate any imperfections. Is is said that you can't over spin a good bullet, but you sure can over spin a marginal or bad one.
Good luck
Jerry
Re: 1x10 or 1x11.25 twist for 7.62?
I have a 5R rock barrel on one of my 700's. It has a 1:11.27" twist. I doubt you'll find anything worthwhile it won't shoot.
I have a 5R rock barrel on one of my 700's. It has a 1:11.27" twist. I doubt you'll find anything worthwhile it won't shoot.
Re: 1x10 or 1x11.25 twist for 7.62?
Depends what type of shooting & how far? Depends on quality of barrel/gun. If it's something along the lines of a Krieger,Rock,Bartlein exc. a 1:11.25 will stabalize about up to a 190 I think.(At least from my experiences) If it's a gas gun too, I don't think anything higher than the 175's will fit in a magazine. The 178 A-max's might fit but I'm not sure. If it were me I would go with a 1:11.25 barrel and shoot 155 scenars or palma's for paper punching or some FGMM. If your wanting to shoot out past 700 with it consistently than go with a 1:10 twist but I assume thats not what your wanting if its a 16-18" gun. Not saying it can't be done but it's just most people don't devote a 16-18" gas gun for target shooting that far. For all around gun I would go with a good barrel in 1:11.25.
Depends what type of shooting & how far? Depends on quality of barrel/gun. If it's something along the lines of a Krieger,Rock,Bartlein exc. a 1:11.25 will stabalize about up to a 190 I think.(At least from my experiences) If it's a gas gun too, I don't think anything higher than the 175's will fit in a magazine. The 178 A-max's might fit but I'm not sure. If it were me I would go with a 1:11.25 barrel and shoot 155 scenars or palma's for paper punching or some FGMM. If your wanting to shoot out past 700 with it consistently than go with a 1:10 twist but I assume thats not what your wanting if its a 16-18" gun. Not saying it can't be done but it's just most people don't devote a 16-18" gas gun for target shooting that far. For all around gun I would go with a good barrel in 1:11.25.
Re: 1x10 or 1x11.25 twist for 7.62?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Get the 10 twist. You won't be shooting the heavier bullets in an AR10 without first modifying the gas system, but the faster twist will ensure better stability of the 168's and 175's if you want to shoot at ranges beyond 600 meters. </div></div>
Really, how does that work exactly?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Get the 10 twist. You won't be shooting the heavier bullets in an AR10 without first modifying the gas system, but the faster twist will ensure better stability of the 168's and 175's if you want to shoot at ranges beyond 600 meters. </div></div>
Really, how does that work exactly?
Re: 1x10 or 1x11.25 twist for 7.62?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Really, how does that work exactly?</div></div>What part? The slower powders necessary for heavier bullets causing hard cycling in gas guns, the lower velocity of the shorter barrel making the 168's and 175's reach the final 10% of their supersonic range sooner, or the influence of drops in temperature and muzzle velocity on optimal twist rate?
It's more productive, and more difficult, to contribute to a thread yourself than to call people out.
Here's some useful info: Bryan Litz has a good discussion of bullet stability and the Miller formula in his Berger 7mm VLD analysis, part 1. http://bryanlitz.bravehost.com/articles/7mmNumberOne.pdf
And here's more useful info on barrel twist from Lija:
http://www.riflebarrels.com/articles/bul...fling_twist.htm
http://www.riflebarrels.com/articles/longrange_shooting/ideal_barrel_308_tactical_rifle.htm
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Really, how does that work exactly?</div></div>What part? The slower powders necessary for heavier bullets causing hard cycling in gas guns, the lower velocity of the shorter barrel making the 168's and 175's reach the final 10% of their supersonic range sooner, or the influence of drops in temperature and muzzle velocity on optimal twist rate?
It's more productive, and more difficult, to contribute to a thread yourself than to call people out.
Here's some useful info: Bryan Litz has a good discussion of bullet stability and the Miller formula in his Berger 7mm VLD analysis, part 1. http://bryanlitz.bravehost.com/articles/7mmNumberOne.pdf
And here's more useful info on barrel twist from Lija:
http://www.riflebarrels.com/articles/bul...fling_twist.htm
http://www.riflebarrels.com/articles/longrange_shooting/ideal_barrel_308_tactical_rifle.htm
Re: 1x10 or 1x11.25 twist for 7.62?
I use the 178 Amax's on my AR10T from the mag, no trouble.
okie
I use the 178 Amax's on my AR10T from the mag, no trouble.
okie
