1/8 or 1/9 twist .308

[grass_hopper]

So I had heard some scuttlebutt regarding 1/8 or 1/9 twist for the .308, the fastest I have heard of stablizing a 175gr HPBT is 1/10. Could this be possible in say a 16" barrel without over twisting and desheaving the round? Or using prgressive twist? What say the hide?

 

[Rob01]

Re: 1/8 or 1/9 twist .308

Unless you are shooting 220-240grn bullets regularly, which the .308 can do but isn't really worth it as slow as they are going, or shooting those heavies subsonic there is no reason for that fast a twist in a .308. Stick with a 10 twist.

 

[buffybuster]

Re: 1/8 or 1/9 twist .308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">Unless you are shooting 220-240grn bullets regularly, which the .308 can do but isn't really worth it as slow as they are going, or shooting those heavies subsonic there is no reason for that fast a twist in a .308. Stick with a 10 twist. </div></div>

+1 to this.

 

[Graham]

Re: 1/8 or 1/9 twist .308

There's a reason nobody does it.

 

[The Animal]

Re: 1/8 or 1/9 twist .308

+1 what Rob said.

If you are going for a heavier magnum in .308 caliber (larger than 300 WM) the twist rate that was recommended to me by the designer of the 300 Norma recommended a 1-9.3 twist for the 240 gr bullets. Anything lighter than the 240's (180-220) go with a 10 twist.

Stay away from 200+ gr bullets with the 308 win. A 308 with 240 gr bullet is like watching a fat woman run up a steep incline. Yes it can happen...but it's not pretty and it's going to take a while to get there! LOL.

 

[slayer 2c]

Re: 1/8 or 1/9 twist .308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Animal</div><div class="ubbcode-body">Stay away from 200+ gr bullets with the 308 win. A 308 with 240 gr bullet is like watching a fat woman run up a steep incline. Yes it can happen...but it's not pretty and it's going to take a while to get there! LOL.</div></div>

That's Great!!!

 

[agr 490]

Re: 1/8 or 1/9 twist .308

Stick with the 1/10. Works no need for a faster in a 308 other than the previosly stated reasons

 

[VKC]

Re: 1/8 or 1/9 twist .308

308win doesn't have enough powder capacity to push such a heavy bullet fast enough to make such a fast twist useful.

 

[gstaylorg]

Re: 1/8 or 1/9 twist .308

Here is a slightly different take on this question, but in specific reference to a 16" barrel as mentioned by the OP. I have the DTA Covert .308 with a 16" 8-twist barrel. Although originally designed with sub-sonics in mind, it is <span style="text-decoration: underline">very</span> accurate with most anything I've tried including 168, 175, and 190 SMKs. It does not "overspin" any of these rounds. Nor does it lose nearly as much velocity as might be expected (avg of around 75 fps slower compared to a 22" 11-twist barrel in the same chassis). Both of these barrels will give the projectile 2 full revolutions within their lengths. Maybe the DTA 16" 8-twist barrel is a little outside normal convention, but it works very well. JMO.

Red_Cell_3, here's a couple links regarding the performance of the 16" 8-twist barrel if your interested:

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1597047&page=13

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1597047&page=16

 

[samnev]

Re: 1/8 or 1/9 twist .308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: agr490</div><div class="ubbcode-body">Stick with the 1/10. Works no need for a faster in a 308 other than the previosly stated reasons</div></div>
+1 on 1:10 twist.

 

[Shooter21]

Re: 1/8 or 1/9 twist .308

I ran a 208 at 2725 out of a 308..... Wouldn't go heavier. I wouldn't go that heavy again

 

[grass_hopper]

Re: 1/8 or 1/9 twist .308

Thanks gstaylorg, GO HUSKERS!

 

[clmayfield]

Re: 1/8 or 1/9 twist .308

The heaviest bullets you can buy will stabilize with a 1/10" BUT heavier monometal bullets such as GS Custom might require 1:9" or faster twist rates. The reason being that to get those bullets heavy enough, they have to make them very long. Very long = difficult to stabilize.

Even then, with a 1:10", you could stabilize some of the lighter monometal bullets while with a 1:9", you are pretty much confining yourself to monometals.

Note that while there really isn't such thing as over-stabilization, the faster you spin a bullet, the more the eccentricity inherent in all bullets causes inaccuracy.