1:8" twist in a .308 Win. short barreled rifle - will it work?

[Jayjay1]

Hey guys,
I want to buy a hunting rifle in .308 Winchester which will be shot both, supressed and unsupressed.

The model I want, and for which I´ve sold my motorbike is made with a 20" barrel with a 1:12" twist, or a 18" barrel with a 1:8" twist.

I would like to have the shorter 18" barrel, but have never heard of a 1:8" twist in a .308 Winchester, I only know twist rates between 10 and 12" in this caliber.
The manufacturer says, they have tried to shorten 1:12" barrels down to 18" and less, some were shooting together, others didn´t.
They are giving a precision guarantee with premium ammo for all of their barrels, for the 18"/1:8" too.

Have you ever heard of such a fast twist in a .308 Win. rifle?

I don´t know what to do.

 

[PinesAndProjectiles]

1:8 seems pretty fast for a 308.

Are you sure it isn’t a typo on their website?

 

[Jayjay1]

Like I said, I have spoken with the manufacturer, I called him.

 

[PinesAndProjectiles]

I was just surfing the Bugholes website and there’s plenty of 30cal barrels with a 1:8 twist.

 

[huntnh]

following

 

[phlegethon]

I was just surfing the Bugholes website and there’s plenty of 30cal barrels with a 1:8 twist.

They are probably intended for 300 Norma Magnum and 300 PRC with heavy bullets like the 250 A tips.

 

[Slides]

If you scale back the muzzle velocity from the 24 inch test barrels to 18 the 8 twist makes sense. Anyone shooting long projectiles (not even solids) in 300wm or larger needs to be 9 twist or below. You aren't going to over spin them.

 

[Jayjay1]

Well, I will shoot solids and jacketed bullets with it.

Of course I want to gain as much speed as possible, but have a short and handy rifle too, especially with the supressor on it.
So I´ve played around with some bullets in QuickLoad and realised, the the velocity will drop around 2% from 20 to 18", fine with me.

Just that a 2" shorter barrel increases the twist rate from 1:12" to 1:8" blows my mind.

 

[fdkay]

Well, I will shoot solids and jacketed bullets with it.

Of course I want to gain as much speed as possible, but have a short and handy rifle too, especially with the supressor on it.
So I´ve played around with some bullets in QuickLoad and realised, the the velocity will drop around 2% from 20 to 18", fine with me.

Just that a 2" shorter barrel increases the twist rate from 1:12" to 1:8" blows my mind.

1-10 has been more of the standard for a few years now.
Yes, there are still plenty of 1-12 twist barrels out there, but it seems that most "tactical" oriented rifles have switched to the 1-10.
FWIW, I have a 1-8 twist on my 11.5 in .330 BO.
I think the success of the BO has driven some of these folks to the faster twists.
I think, for the bullets you are likely to shoot (nothing higher than a 178) a 10 twist would do fine, however, to shoot the 185's and higher, you would likely be better served with that 1-8.
Accuracy likely won't be stellar with the lightweights.

 

[phlegethon]

If you scale back the muzzle velocity from the 24 inch test barrels to 18 the 8 twist makes sense. Anyone shooting long projectiles (not even solids) in 300wm or larger needs to be 9 twist or below. You aren't going to over spin them.

That’s not how it works. Decreasing barrel length by 25% doesn’t decrease velocity by 25%. While I doubt bullets will blow up from a 308 with an 8 twist, there will be no benefit and accuracy will suffer needlessly.

 

[Slides]

I'm not suggesting velocity is proportional but you are talking what, near 200fps? People are shooting hot 308 or various magnum loads from 10 twist and tighter in 30 inch barrels over 3000fps that shoot fine, that's ~20% faster than what the 18 will do so 8 should be fine. If you are only using 130-150 lead core a 12 is probably fine too. I wouldn't let the twist put you off if you prefer that length.

Alternatively, get something in 45-70 with a 20 twist.

 

[SharpsNitro]

The Desert Tech 16” .308 barrels for the SRS are 1:8 twist and shoot well.

 

[C-grunt]

I recently shot a 16 inch Larue OBR (1in10 twist) out to 1030 yards using FGMM 175s. No issues.

Ive shot a shorty 308 with a fast twist around 1in8, I cant remember exactly, but it was built like that to shoot subs.

 

[FCS]

Well, I will shoot solids and jacketed bullets with it.

Of course I want to gain as much speed as possible, but have a short and handy rifle too, especially with the supressor on it.
So I´ve played around with some bullets in QuickLoad and realised, the the velocity will drop around 2% from 20 to 18", fine with me.

Just that a 2" shorter barrel increases the twist rate from 1:12" to 1:8" blows my mind.

Shooting monolithic, especially long ogive monolithic, you’ll benefit (read need) a faster twist for the bullets to be reliably stabilized and perform across board.
8 isn’t really needed for most cup/core bullets but once you add monolithic to mix, more twist is more better.
YMMV so keep asking questions and gathering info so you can make an informed choice.

 

[Winny94]

FWIW, the KBs of the world are moving to ungodly fast twists for their subsonic offerings (300 blk @ 1:5, 338 federal, or whatever the derivative is being called at 1:3)

 

[Crews]

Well… you obviously think this is a competent manufacturer since you’re buying their product…. so why not just trust that they know what they’re doing?

 

[Missalot]

What hunting bullets are you planning to use and do you plan to shoot any subsonic?

 

[Jayjay1]

Thanks guys,
so the 1:8" twist rate for the 18" barrel is in fact more stable and more suitable than the 1:12" in the 20" barrel.

I never would have guessed that.

Thanks a lot.

 

[Jayjay1]

What hunting bullets are you planning to use and do you plan to shoot any subsonic?

Well, what is suitable, solids and jacketed bullets (in some areas solids are required).

Jacketed from around 150 to 180grs., solids from 130 to 165grs. I guess.

 

[richthe1]

I’ve been wondering the same. One interesting thing is the Army’s new Barrett MRAD (MK22) 20” 308 barrel is a 1:8 twist. Thought it was a typo at first as I know 1:10 is “the norm”. If the army is doing it I guess there’s a reason!

 

[Jayjay1]

Will the faster twist rate affect the shooting?

Maybe I´m wrong, but will the rifle get more torque, the bullet less speed and be there more recoil, or is this just nonsense?

 

[theLBC]

i heard somewhere that a fast twist may not be ideal for cheap m80 ammo, but i don't know for realz.

 

[celltech]

Does Barrel Twist Rate Affect Muzzle Velocity? (Litz Test) « Daily Bulletin

The Applied Ballistics team tested six (6) same-length/same-contour Bartlein barrels to observe how twist rate might affect muzzle velocity. This unique, multi-barrel test is featured in the book <a href=http://www.amazon.

bulletin.accurateshooter.com

 

[jcmullis2]

I wouldn’t risk several hundred bucks just to find out why 1:10, 1:11.27 or 1:12 are typically used.

 

[Im2bent]

Will the faster twist rate affect the shooting?

Maybe I´m wrong, but will the rifle get more torque, the bullet less speed and be there more recoil, or is this just nonsense?

According to the article celltech posted there will be zero velocity loss. So yeah its a nothing issue. Alot of barrels are going to faster twists so you can go heavier/longer bullets.

 

[phlegethon]

According to the article celltech posted there will be zero velocity loss. So yeah its a nothing issue. Alot of barrels are going to faster twists so you can go heavier/longer bullets.

There will be accuracy loss. Not velocity.

edit: as above, the .30 cal bullets that need a 1:8 twist are the 250 grain A-tips. Not anything you’d shoot from a .308.

 

[coldboremiracle]

Hell yes it works, and 16" 308s are outstanding! I have had one for years, its one of my favorites.

 

[Winny94]

There will be accuracy loss. Not velocity.

edit: as above, the .30 cal bullets that need a 1:8 twist are the 250 grain A-tips. Not anything you’d shoot from a .308.

Thats contrary to what several are doing now. Faster twist is showing to be more accurate in subsonic applications. What makes you say that? (or are you referring only to supersonic?)

 

[phlegethon]

Thats contrary to what several are doing now. Faster twist is showing to be more accurate in subsonic applications. What makes you say that? (or are you referring only to supersonic?)

Yes, of course I’m referring to supersonic. .308 Winchester is a supersonic cartridge.

 

[Huskydriver]

I use 1/8 twist 308 barrels for dedicated subs with 220 gr bullets

Eta barrels are 16"

 

[Winny94]

Yes, of course I’m referring to supersonic. .308 Winchester is a supersonic cartridge.

ummm...no? It can absolutely do both.

 

[XP1K]

I had a model 700 built years ago in 300blk when that cartridge first came out. 1:8 twist lilja on it parted off at 16". It shot everything from 110 Sierra hollow points to 225 amax's. The 110's would were consistently 1/2 moa and the 225 sub loads shot just over 1 moa.

Never could get it to extract right. It would let go of the case halfway out and you always had to shake it out. Ended up rechambering to 308 to shoot mostly subs but I had better full power options as well. It would shoot factory hornady 168 match in the 1/4 moa range! Subs still ran about the same.

I got to thinking I didn't need three 308's around and sold that rifle to my cousin. I see it now and then and when I do I'm usually kicking myself for letting go of it. Tried to buy it back several times but he won't come off of it.

 

[phlegethon]

ummm...no? It can absolutely do both.

OK, you win. It’s very reasonable to build a 308 and intend to shoot it subsonic, and lots of people are doing that all the time. And the idea that overspinning bullets makes them less accurate has nothing to do with physics, but was just an obsolete fashion trend. Why stop at 8? Why not try 1:6.5? It’s done wonders for .224 Valkyrie….

 

[Skunk]

My experience with 16" 8twist 308's has been... less than stellar. And, this is a sample size of several hundred guns, that many different shooters (of varying skill level), but pretty much all shooting Fed Gold Medal 168 Match. Compared to a good 10twist, they just suck.

If you think 50% or more of your shooting is going to be subsonic with 200+ grain projectiles, sure, go for it. But, otherwise... 10twist and be happy.

 

[jcmullis2]

I wouldn’t chance my motorcycle money on a accuracy guarantee. Say it doesn’t shoot like they said, you don’t think they’re gonna give you your money back do you? At best they’ll try to fix it. They’ll probably leave it in the pile for 6-8 months and send it back to you bruised and gouged all to hell and still shooting 3moa groups.

 

[Winny94]

OK, you win. It’s very reasonable to build a 308 and intend to shoot it subsonic, and lots of people are doing that all the time. And the idea that overspinning bullets makes them less accurate has nothing to do with physics, but was just an obsolete fashion trend. Why stop at 8? Why not try 1:6.5? It’s done wonders for .224 Valkyrie….

Your hostility is confusing. Are you upset people shoot subsonic, or....whats your issue?
And you're being rhetoical, but there is something to be said for extremely fast twists shooting heavy 30 cal bullets - even down to 1-5". So not sure who you're mad at (or why), but direct it elsewhere.

 

[coldboremiracle]

My experience with 16" 8twist 308's has been... less than stellar. And, this is a sample size of several hundred guns, that many different shooters (of varying skill level), but pretty much all shooting Fed Gold Medal 168 Match. Compared to a good 10twist, they just suck.

If you think 50% or more of your shooting is going to be subsonic with 200+ grain projectiles, sure, go for it. But, otherwise... 10twist and be happy.

Thats wierd, the Desert Tech SRS Covert uses a factory 16 inch 8 twist barrel, and they have sold hundreds if not thousands that all come with a 1/2 MOA guarantee. I love mine, it certainly doesn't suck.

 

[Skunk]

Thats wierd, the Desert Tech SRS Covert uses a factory 16 inch 8 twist barrel, and they have sold hundreds if not thousands that all come with a 1/2 MOA guarantee. I love mine, it certainly doesn't suck.

I'm glad your experience has been different from mine.

 

[ohiofarmer]

Skunk, can you not mention where you encountered hundreds of 1:8” .308s? I read that and assumed they were gas guns, but were they bolt actions that struggled to get the accuracy? (All things being equal except for the 1:8” v. 1:10”?)

 

[Skunk]

A certain govt agency has 400+ bolt actions which were once 24" 12twist. They shot great but were a little behind the times as far as configuration/deployability. They were reconfigured/re-barreled and now they struggle to hold 1moa.

To be fair, the work was not completed by "accomplished" rifle builders (my opinion), and many components were changed at the same time, so it's difficult to say exactly what the problem with the system is. But, I'm pretty confident in the optic, the Badger hardware, MDT chassis, Geissele trigger and the ammo.

 

[phlegethon]

Your hostility is confusing. Are you upset people shoot subsonic, or....whats your issue?
And you're being rhetoical, but there is something to be said for extremely fast twists shooting heavy 30 cal bullets - even down to 1-5". So not sure who you're mad at (or why), but direct it elsewhere.

I’m irritated by the stupidity in this thread.

 

[Jayjay1]

I agree with phlegethon, it started not to bad, came early to a conclusion, and now there is a lot of bullshit inhere.

Caliber, barrel length / velocity and twist rate have to be in a certain proportion to gain a propper twist rate.
In general a slower twist is more of an issue than a faster twist, because under-stabilization causes bullets to tumble.

Very much in the beginning of this thread reubenski posted a link to the twist rate calculator from Berger (Brian Litz if you have heard of him).

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

With this calculator you can compute the stability of the bullet.

A shorter barrel leads to a lower velocity which needs a faster twist rate to still stabilize the bullet.

So, who wrote a lot of BS inhere?

 

[308pirate]

A certain govt agency has 400+ bolt actions which were once 24" 12twist.

Are they expecting a war?

 

[pmclaine]

I got a build in progress now and this is the Bartlein spec....

.308 cal. Barrel .300 x .308, 5R rifling, "T" style 1-9.5 to 1-8.75 twist, C.M. 1.200" x 4", straight taper to .900" @ 21" finish, 22" blank **LEFT HAND**

I hope faster than traditional twist works....

 

[Jayjay1]

Regarding the Berger twist rate calculator, a faster twist is not an issue, a slower twist might be, especially with shorter barrels aka lower velocities.

 

[Slides]

I wouldn’t risk several hundred bucks just to find out why 1:10, 1:11.27 or 1:12 are typically used.

By old fashioned F class fudds running hot long loads of 155gr projectiles in 30 inch barrels in single feed actions. Completely different to factory or regular hand loaded hunting ammo and the effective bullet rpm will be pretty much the same with 500fps higher speed.

I know that even with 30 inch barrels so e of them are struggling to stabilise modern 155gr projectiles from 1:12 and 1:11 twist barrels over 3000fps.

 

[pmclaine]

Its not the bow, its the Indian.......

 

[pmclaine]

Are they expecting a war?

General Milley just wants to be ready when the "right" armed coup opportunity comes along........you know they have to go through him, he has the guns.

 

[308pirate]

General Milley just wants to be ready when the "right" armed coup opportunity comes along........you know they have to go through him, he has the guns.

I was just wondering why any law enforcement agency needs 400+ bolt action rifles.

Does the USMC even have that many?

 

[pmclaine]

I was just wondering why any law enforcement agency needs 400+ bolt action rifles.

Does the USMC even have that many?

There are more "PWS Built" rifles in civilian hands than ever built at PWS.