What Barrel Length and Twist for a 270WSM Build

Jmathis

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Dec 15, 2020
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Montana
I am building a wsm as well. I think I'm going with a 1-7 twist. Plan is to build some 170s for LR, and run a 150 for hunting. I am probably going to run a xcaliber, carbon.
 

Ranger Rick

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Sep 6, 2019
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Idaho
The above recommendations are spot on with either a 24" or 26" barrel with a twist in the range of 1:8' to 1:9" (LRH is a great forum :)). There are several fantastice barrel makers out there, to name a few: Bartlein, Brux. Krieger, Proof Research. The barrel makers support staff that I have dealt with have been knowledgable and a pleasure to talk with on the phone. I'd recommend calling some companies.
I prefer single-point cut rifling over button rifling (a topic in itself), twist options are precise such as 1:8.7" = exactly what you request. Gain twist is an option and I will be putting a 1:9.4' to 1:8.7" gain twist Bartlein barrel on my Rem 700 BDL 7mm Mag this Spring. On the barrels that I have ordered without gain twist, I look for companies that also hand lap their barrels. I've found that new barrels that are lapped are easy and quick to break in.
With CNC machineering blended with traditional high quality professionals, getting a new barrel is a wonderful experience. Then, a gunsmith that will chamber your new barrel to your favorite bullet is an added benefit of rebarreling. All in all, a new barrel makes for a great Christmas present!
Merry Christmas.
 
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Jell101

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Jun 14, 2016
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Georgia
Just a few years ago I had a model 70 built. It’s a 1:8 twist Bartlein 26in threaded. Like others have said the lighter bullets shoot great but mine was built to shoot the heavies. The 170gr Berger’s shoot great. Mine is also heavier than some want to carry at 9.5 lbs. Being from the south east US I do hunt deer with it in open pine flats but it does get kind of long for thick woods. When we hunt out west it’s great.
 

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.300 Dakota

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Moss Point, MS
Whether you require faster than 1:10 depends solely on whether you intend to shoot the Berger EOL Elite 170 grain bullet, but you definitely need a minimum of a 26" barrel for a 270 WSM. All the factories, especially Browning with their 23" has it WRONG! That's precisely why you need to create custom work and why there's a high demand for it.
 

Shortmagman

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Feb 22, 2008
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Memphis Tn
I faced the same thing a few years ago. I had shot out the barrel on my Winchester Model 70 in 270WSM. I went with a Bartlein 24 in 1in9. I do not shoot bullets over 150 grains. My new barrel loves 150 VLD Bergers.
 

Raudy707

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Apr 16, 2018
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Mendo
Whether you require faster than 1:10 depends solely on whether you intend to shoot the Berger EOL Elite 170 grain bullet, but you definitely need a minimum of a 26" barrel for a 270 WSM. All the factories, especially Browning with their 23" has it WRONG! That's precisely why you need to create custom work and why there's a high demand for it.
Don't forget about Matrix the Hammer bullets and Nosler 165 ABLR. The 139 Absolute Hammer requires 1:9 and the 156 Hammer Hunter 1:8. The Barnes 150 TSX & Noz 165 ABLR again 1:9. You never know what is going to shoot well out of your barrel so might as well give yourself as many options as possible. Matrix is closed I think but they may come back. If this 270 fast twist thing starts catching on more high BC bullets could be offered in the not to distant future. I like your recommendation of a 26 inch barrel. Definitely not under 24 or just might as well get a 270 win.
 

SSG Graybush

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Aug 13, 2020
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Winchester VA
Thanks for all the good replies.

I checked out Berger’s Twist Rate Calculator and looks like anywhere from a 8:1 to 10:1 would work for a 140gr to 150gr bullet. But when I go to the 170gr VLD it looks like I want a 8.5:1 minimum. Do the barrel guys even make a 8.5:1 or are you limited to 8:1 or 9:1?

If I went with a 8:1 over the 9:1 what would I be giving up with the 140s and 150s? Anything? Or in other words, why would I not want to go with a 8:1 since it'll also handle I talked to Berger tech

I finally shot the barrel out of my 270WSM. I’m going to have it rebarreled and customized… action trued, lug pinned, and bedded. I own a couple custom sticks but have never built my own. I’m going to stick with the 270WSM caliber and the primary purpose will be hunting, mostly deer type game. I handload and currently use 140gr accubonds in my load of choice but would also like to maintain some bullet flexibility for the future.

I’ve never built my own rifle so wanted to tap some of the experience on here and see what folks would recommend for barrel length and twist? I don’t need a 1000yd gun with this one. Maybe 800yd range gun and 600yd hunting rig. Weight is a consideration but I don’t need an ultralight mountain gun.

It’s going to be one of my all around general purpose hunting rigs.

Thanks for any insight.
I talked to the Berger tech guy and the 170 EH needs a long action. I would do a 9T 24 inch barrel and shoot the 150ish gr bullets out of a SA. I shoot 130 gr Berger CH's at only 3089 fps. It does the job at .5 moa sd of 7.
 

Andrew Massi

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Jun 4, 2018
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Lincoln Ca
I talked to the Berger tech guy and the 170 EH needs a long action. I would do a 9T 24 inch barrel and shoot the 150ish gr bullets out of a SA. I shoot 130 gr Berger CH's at only 3089 fps. It does the job at .5 moa sd of 7.
Handicapping a cartridge to stay in a short action is counterintuitive nowadays. There's better ways to save 2oz
 

skipglo

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Jan 23, 2015
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Alberta
I finally shot the barrel out of my 270WSM. I’m going to have it rebarreled and customized… action trued, lug pinned, and bedded. I own a couple custom sticks but have never built my own. I’m going to stick with the 270WSM caliber and the primary purpose will be hunting, mostly deer type game. I handload and currently use 140gr accubonds in my load of choice but would also like to maintain some bullet flexibility for the future.

I’ve never built my own rifle so wanted to tap some of the experience on here and see what folks would recommend for barrel length and twist? I don’t need a 1000yd gun with this one. Maybe 800yd range gun and 600yd hunting rig. Weight is a consideration but I don’t need an ultralight mountain gun.

It’s going to be one of my all around general purpose hunting rigs.

Thanks for any insight.
I am very partial to 26" barrels and for your build 1:8. Just me!
 

Jmathis

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Dec 15, 2020
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Montana
I would go a 24" to 26" tube, 1:8" twist, flute the barrel and run a #6 straight taper. I have had great success with that combo with friends and clients with various calibers.
I am going to have to go at 7 or 7 and 1/2, the company I'm working with does not offer an 8. Would you recommend a 6 groove, or a 5r twist?
 

Jell101

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Jun 14, 2016
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Georgia
My model 70 is a SA. As you can see in my picture 170EOL is long. I don’t think you have to have a LA. It can be done on a SA you just have to watch the mag box. I am also not using mine a a single shot. It only holds 3 in the box but it works for our hunting needs. I am not pushing the upper limits of speed either. I found the node it liked and .5 groups at 100 without fine tuning or trying a lot of different powders.
 
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