How to get fast twist barrels in NZ

Im after a pair of barrels one in 338 cal and one in 30 cal

the trick is I want absurdly fast twist rates (1-5 for the 30 and 1-3 for the 338)

or basically as fast as possible as I can get my hands on.

Pacnor was awesome for doing this but they have recently had a fire

trueflights 1-8 premium suppressor is about as fast as I have found locally but before I go with that i'm keen to see if there's anything Iv missed

Why? they are both for subsonic rifles, and faster twist rates deliver more energy and stability with the bullets I want to use

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Originally Posted by Bill999

Im after a pair of barrels one in 338 cal and one in 30 cal

the trick is I want absurdly fast twist rates (1-5 for the 30 and 1-3 for the 338)

or basically as fast as possible as I can get my hands on.

Pacnor was awesome for doing this but they have recently had a fire

trueflights 1-8 premium suppressor is about as fast as I have found locally but before I go with that i'm keen to see if there's anything Iv missed

Why? they are both for subsonic rifles, and faster twist rates deliver more energy and stability with the bullets I want to use

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What are these projectiles? Do, pray tell

@Bill999
Sound silly
I like silly projects because you learn things you didn't know

I have a mate who makes barrels commercially and has the barrel drills for what you want.
I just know he won't have the rifling buttons that fast because he's tapped out at 1:7 on the 30

But he might be able to get much faster buttons.
How much faster i don't know
But he will be visiting me today or tomorrow for a toy swap around and i can mention it to him

You're welcome to pm me and we can make direct contact and i can fill you in on who and what and where

@Bill999 , it looks like you watched that video about the 338 creedmoor or something like that.
I am not convinced that Going super fast twist in 338 will bring any real benefits as they pretend in that video.
We will see how it works for you once you build that rifle. Good luck with the project.

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Originally Posted by akaroa1

@Bill999
Sound silly
I like silly projects because you learn things you didn't know

I have a mate who makes barrels commercially and has the barrel drills for what you want.
I just know he won't have the rifling buttons that fast because he's tapped out at 1:7 on the 30

But he might be able to get much faster buttons.
How much faster i don't know
But he will be visiting me today or tomorrow for a toy swap around and i can mention it to him

You're welcome to pm me and we can make direct contact and i can fill you in on who and what and where

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I did have a chat over email to that chap about 338 barrels and with current tooling 1-9 is as fast as he has currently because that's what's in demand, Iv recently picked up another rifle to do a 300 black out with so i am going to concentrate on that till more info on 8.6 creed comes out in the next few months
The guy from Vulcan was a top bloke I would be keen to hear what he can do in a fast twist 30cal

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Originally Posted by Bill999

I did have a chat over email to that chap about 338 barrels and with current tooling 1-9 is as fast as he has currently because that's what's in demand, Iv recently picked up another rifle to do a 300 black out with so i am going to concentrate on that till more info on 8.6 creed comes out in the next few months
The guy from Vulcan was a top bloke I would be keen to hear what he can do in a fast twist 30cal

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Vulcan 1:8 30 1:9 338

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Originally Posted by Moa Hunter

What are these projectiles? Do, pray tell

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Perigrine and Lehigh subsonic expanders

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Originally Posted by Friwi

@Bill999 , it looks like you watched that video about the 338 creedmoor or something like that.
I am not convinced that Going super fast twist in 338 will bring any real benefits as they pretend in that video.
We will see how it works for you once you build that rifle. Good luck with the project.

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I'm keen to give it a shot, things I will need arnt really available yet around the 8.6creed so I'm going to put that on the back burner and give more information a chance to come out.
Apparently the 1-5 twist barrels in ar15 blackout pistol length barrels work really well. I'm looking at a 11 inch barrel (breachface to barrel end) and slower twists are ok in longer barrels where there is more time in the barrel for the bullet to stabilise. I'm fitting in somewhere between these two with short but not super short.
At this stage my plan is to send it to trueflight and get ask them to fit a premium suppressor 1-8, unless I can find something a little quicker twist

Surely twist is twist
Longer barrel shouldn't make a difference to the bullet twist just the speed

Its not like they slip and then grip and twist
They grip and twist all the way as they accelerate ( surely)

Speed will be set at about 1000fps so all I'm hoping for is accuracy

Ive done a lot of work with sub loads in these cartridges over the years and I cant see any advantage of going to such fast twist barrels for them.. in fact I think you will find they will actually add more issues than advantages such as higher case pressures and wobbly over stabilised bullets.
Hornady is just trying to baffle us with the marketing BS one again.

A history lesson for you may better explain. Back when the late J D Jones thunk up the Whisper idea his intentions were to use the heaviest bullets with the highest BC's in a cartridge just big enough to shoot in the subsonic realm in a fast twist barrel that could stabilise such a bullet at low speeds.
For reference I will only speak of the .300 Whisper and the .338 whisper as this is what you have shown interest in.
JD used Shilen to make custom barrels for him for this venture and his twist rate was 1-8" for both the .300 and the .338 cartridges.
At the time the heaviest bullets available for these two were the Wildcat bullets which were 250gr in .308 and 350gr in .338 which were perfectly stable to 1000 yards with a 1050fps muzzle velocity in these 1-8" twist custom barrels.

Attachment 123269

Attachment 123270

Later due to more commercial availability they advised and used the Sierra match king 240gr in .308 and 300gr in .338, both of which were also perfectly stable at sub velocities out to 1000 yards. Why? because that's the twist rate JD settled on after a LOT of testing with custom Shilen barrels.

Fast forward to modern day... enter military contracts and the need for the .300 whisper to be Saami spec, out it rolls with a brand new name... .300 Blackout. This also brought popularity and more availability to components for both rifles and ammunition. While JD discovered that the 1-8" twist was by far the most accurate twist for the .300 Whisper with the 240 and 250gr .308 bullets, the trend was for the shorter AR15s to go to a 1-7" twist and a lighter 180gr to 220gr bullet at sub speeds. You guessed it... The shot like crap compared to the heavies through the 1-8" Shilens... but the single ragged hole subsonic groups had long been forgotten with the requirement for military units to only perform to MOA at 100y.

The crazy thing in all this marketing hype is actually the fact that now we have all these lighter weight special expanding subsonic well balanced bullets the twist rates should actually be getting slower not faster.
Take the new Hornady 190gr SubX bullet for example, it is stable at sub velocities out of a 1-10" twist.

The .338 350gr Wildcat bullet was stable in the 1-8" Shilen barrel but not in the Trueflight 1-9 barrel. The 1-9" truflight only just stabilises the 300gr SMK and not the 300gr Berger VLD at sub speeds so a 1-8" is the best for the .338 for the longest bullets in its class. once again the new expanding sub bullets in .338 are lighter and shorter so a 1-9" or even 1-10" will work fine.
Here is the Berger VLD (Left) and SMK (right) side by side, not a big difference which suggests the 1-9" is borderline to slow for these 300gr heavies at sub speeds:

Attachment 123271

While it seems Hornady is doing ground breaking stuff... they are just to re-invent the wheel, it has all been done before only on a lesser marketing budget.
8.6 Creedmoor is nothing more than the .338 Whisper which is a 6BR or 7BR cartridge necked up to .338.
once Remington stopped making 7BR brass I started to make my own using stronger Lapua SRP .308 Palma brass in the same fashion you can make .300 whisper/BLK brass from .223Rem brass.

Attachment 123272

Attachment 123273

Here are a couple of links to threads Ive started previously dedicated to this topic if you are interested:

https://www.nzhuntingandshooting.co....-300blk-44679/

https://www.nzhuntingandshooting.co....-300blk-44692/

Personally I think if I was to build another subsonic rifle Id lean toward one of @Kiwi Gregs 8.6x47 Lapua's.
Much better brass and the flexibility to load viable high velocity lighter bullet loads for longer shots if needed.
Not sure if the 1-8" .338 Shilen barrels are still available but that would be my first choice, or a 1-9" true flight would be fine in that.
Do you have the chamber reamer for that one Greg or was it just a 6.5x47 lap followed up with a .338 N&T reamer?
I considered a 6mm Norma Dasher necked to .338 with its slightly longer brass and 40 deg shoulder compared to the shorter the 6BR with the 30deg but I think this 8.6x47 Lap will make the most of a short action and multi purpose loadings.

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Originally Posted by Wingman

Personally I think if I was to build another subsonic rifle Id lean toward one of @Kiwi Gregs 8.6x47 Lapua's.
Much better brass and the flexibility to load viable high velocity lighter bullet loads for longer shots if needed.
Not sure if the 1-8" .338 Shilen barrels are still available but that would be my first choice, or a 1-9" true flight would be fine in that.
Do you have the chamber reamer for that one Greg or was it just a 6.5x47 lap followed up with a .338 N&T reamer?
I considered a 6mm Norma Dasher necked to .338 with its slightly longer brass and 40 deg shoulder compared to the shorter the 6BR with the 30deg but I think this 8.6x47 Lap will make the most of a short action and multi purpose loadings.

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When we made my 338 BRX AR15 upper we cocked up & used 338 Whisper reamer which meant the throat was too long for the projectiles I wanted to run & they were crap :(

The 160 TTSX on the other hand went fantastic, 1/2 to 3/4 moa was easily achievable at 25-2600 fps with a 20" barrel, it was an awesome upper on a 1-9 True-Flite barrel :cool:

I wanted more case capacity for its replacement only having a 11.75" barrel to get 2600 fps & still easily keep it in a magazine.

We used a 6.5 x 47 Lapua & 338 Federal reamer to make the chamber :)

Thanks for these responses guys it's cool to hear what people with previous experience have found to be successful.
Ruger 300blk Americans stack hornady sub x from what I have seen out of my friends with their 1-7 barrels
I would really like the opportunity to buy off the shelf top quality sub rounds like sub-x if it's just picking a case out of a hat as things seem to be between the 223 and 308 case size in all of these sub rounds. Purely for convineience and availability, I'm not interested in case forming

FWIW the Bergara B 13 takedown 308 is 1:8” twist...16” barrel.

the rifle will be on its way to Trueflight to get one of their 1-8 Prem supp barrels fitted some time in the next six weeks

Quote:

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Originally Posted by akaroa1

@Bill999
Sound silly
I like silly projects because you learn things you didn't know

I have a mate who makes barrels commercially and has the barrel drills for what you want.
I just know he won't have the rifling buttons that fast because he's tapped out at 1:7 on the 30

But he might be able to get much faster buttons.
How much faster i don't know
But he will be visiting me today or tomorrow for a toy swap around and i can mention it to him

You're welcome to pm me and we can make direct contact and i can fill you in on who and what and where

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@homebrew.357 has a rifling machine, maybe the right solution for those insane twist rates. A button has got to be slipping a bit at 1:3

When the ratio is inverted ,you don't call is a button anymore but a tap :-)

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Originally Posted by Friwi

When the ratio is inverted ,you don't call is a button anymore but a tap :-)

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Ha ha!
"What twist rate are you running mate?"
Errrrr... .308" BSP

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Originally Posted by Cordite

@homebrew.357 has a rifling machine, maybe the right solution for those insane twist rates. A button has got to be slipping a bit at 1:3

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I did ask but there was some shortfall

I hear rifling buttons are pricey

Sounds like the goal is to get the heaviest, highest BC possible projectile, shooting at just under the speed of sound, out of a short action. Sound about right?

Its not very unique, but personally I think when the number crunching is done, the 30cal is going to be a better choice. Arguments for the .30cal diameter are as such.

Projectiles are literally half the price of comparable .338 projectiles.
Hornady 225gr ELDM with a BC of .777 are $99 per hundred, vs .338 .300gr Sierra matchking with a BC of only .768 (thats less than the .30cal) at a cost of $99 per FIFTY.
Berger .300gr have a marginally better advertised BC of .822 but its not going to make much of difference at the ranges this gun would be capable of, and again they are double the cost of a comparable 30cal projectile.
You could shoot the Hornady 225gr .338 ELDX projectiles which are comparable in price to the .30cal ELDM but then you take a significant BC hit vs the .30 and loose the one advantage that the .338 may have, which is a heavier projectile on target.
A suitable twist barrel to stablise heavy 30cal will be much easier to come by than a .338

I ran some numbers to put it into perspective.

.30cal 225ELDM @ 1000fps.
Cost per projectile = (roughly) .99c each.
100m = zero
200m = 43clicks or 4.3mils of elevation required/17MOA elevation required. Energy at 200m = 449ft/lb
300m = 100 clicks or 10mils of elevation / 40MOA required. Energy at 300m = 428ft/lb
400m = 159 clicks up or 15.9mils of elevation required / 62.6MOA. How much does your scope have?
500m = 221 clicks up or 22.1mils / 87MOA of elevation required. 391 ft/lb energy remaining. Safe to say the effective range is well passed.

Now for the .338. Iv picked the .338berger to give the 338 as gooder showing as possible.
.300gr Berger OTM / Elite Hunter at 1000fps.
Cost per projectile $1.85 each.
100m = zero
200m = 43 clicks or 4.3MIL elevation. Exactly the same elevation required as the .30 cal. Energy = 602ft/lb. (Same elevation as the .30)
300m = 99clicks or 9.9MIL up), or 38.97MOA. Energy = 574ft/lb (one single click advantage over the .30)
400m = 158clicks or 15.8MIL up, or 62.2MOA. Energy = 550ft/lb. (one single click advantage over the .30)
500m = 21.9MIL / 219 clicks up (mil), or 86.2MOA. Energy = 527ft/lb. (two clicks advantage over the .30)

When all is said and done, there is only 2 clicks elevation difference at 500m between the .30cal projectile at 1000fps and the .338 berger .300gr at 1000fps. I cant see this setup going much further.
There is only a 136ft/lb advantage to the .338 at 500m. Is that worth literally double the cost of the .30cal projectile and the hassle that goes with piecing together a suitable setup to shoot them?
I purposely went the "reasonably priced" projectile route with the .30cal with my point being the gains arnt worth the difference in cost (imo), but if you wanted to spend ,338 dollars on .30cal projectiles then some A-tips would probably put the .30 subsonic ahead in all respects.

If you just want something cool and unique, then more power to you. Do it. There needs no justification for cool stuff. But from a numbers point of view it does not make much sense, to me.

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Originally Posted by Wingman

Ha ha!
"What twist rate are you running mate?"
Errrrr... .308" BSP

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Nah, a Witworth :-) ( if you know your rifling and your threads you ll get the idea ;-)

Thinking about this more, I think a good option could be to get a fast twist .308, throated short, so you can fit 220gr + projectile in the mag and still be close to the lands.
Brass , dies , projectiles etc will be as easy as it comes . Projectile will be real deep in the case and take up lots of case capacity, but who cares it’s not needed because subsonic, and you will still be close to the lands and mag feed = win

That was the video on the 8.6 credmoor and the fast twist:
https://m.youtube.com/watch?v=RVchYB2vOjg

458 socom is another option :

https://m.youtube.com/watch?v=ijDGqYjXAiM

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Originally Posted by ChrisW

Thinking about this more, I think a good option could be to get a fast twist .308, throated short, so you can fit 220gr + projectile in the mag and still be close to the lands.
Brass , dies , projectiles etc will be as easy as it comes . Projectile will be real deep in the case and take up lots of case capacity, but who cares it’s not needed because subsonic, and you will still be close to the lands and mag feed = win

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You and Dean Maisy share the same opinion, I have a suppressed 308 already and just want something smaller and lighter with less case capacity for hopefully less noise
my 308 runs Roberts 151gr hollow points well, and I will use them in this 300 BLK as well as they are good projectiles and the cost factor makes shooting rabbits and things with them far more reasonable. Im not sure I would have had much success using with them in a 1-5 twist with excessive leading

I have a 450BM in the cabinet but to be honest its subs are not that quiet in comparison to 308, the 77/44 i have running 44special cow boy loads is better but they are both quite a big step up in sound

I use my 308 at least 4 days a week I just want something shorter, lighter and quieter

im still looking at doing the 8.6creed but i want to see some more components that I need become available mostly barrel, reamer, cases, loaded hornady subx. I have the donor rifle ready

till then a 300 blk will keep me more than happy

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Originally Posted by Friwi

Nah, a Witworth :-) ( if you know your rifling and your threads you ll get the idea ;-)

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Unf? Get it real right?

so your telling me I can just mig a whole heap of 30cal nuts together and make my own barrel? i could get into the octagonal barrel look. haha

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Originally Posted by Bill999

I did ask but there was some shortfall

I hear rifling buttons are pricey

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Not super pricey, can get some from china, get from ukraine or somewhere too (both on ebay) which the latter claim will withstand being hammer driven. May need an import license in the current clampdown victimisation of NZ shooters post Chch. Heard of someone needing an import permit for a .22WMR chamber reamer!

Problem with buttons as far as I understand it from the bumf on the sites is that you need a rather fat walled barrel for the button to work (if you do it on a thinner walled barrel the barrel expands around the button rather than accepting a groove indentation). The barrel is subsequently turned down to the preferred contour. Probably some do button rifling on thinner walled tube using different calculations, but any diameter barrel can be accurately rifled with a traditional rifling machine using cutters rather than buttons.

China: https://www.ebay.com/itm/5-5-11-43mm...l/232877632646
Ukraine: https://www.ebay.com/itm/Rifling-But...y/152951198885

I watched a video on those cheap buttons on youtube and they were nothing more than trash, i doubt either vulcan or truefight would even entertain the idea and risk their reputation on anything less than the industry standard