.277 Fury Barrels

scottneh

Private
Minuteman
Sep 12, 2023
3
1
New Mexico
HinAll, the 6.8x51 / .277 Fury has been out there a year now. I'm curious if anyone has seen commercial or semi-commercial AR-10 platform barrels out there that can handle the high 80kpsi pressure yet. I've heard there is a proprietary metallurgy to the gov barrels so not sure if any experimenters out there have made something close yet. I have seen some SS barrels but they are limited to 68Kpsi
 
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I don’t think many, or any, manufactures are going to support the .277 Fury in the AR-10 platform. Why would they given the increased liability? There might be bolt heads and extensions out there that can handle the pressure, but it sounds like a lose-lose proposition for companies to offer a barrel on a platform it was never designed for.

edited to add - handling the pressure for a dozen or even a couple of hundred rounds doesn’t mean it’s safe over a lifetime.
 
There’s a recent interview with SIG where they said they backed down on the pressure because it was causing issues with early accuracy loss. I believe they said that 70,000psi was more of a sweet spot for that.

They said barrel life was determined by accuracy and velocity losses outside of a certain range, and threw out a rough 4000rds barrel life given their performance thresholds.

In other words, you can match the downrange performance with a 7mm SAW or 7mm-08 Improved, without chasing high chamber pressures.
 
I had some interest so I googled it and came up with this:


After reading some of the SHTF threads on the hide I decided not to spend the money on a new caliber, but to get more ammo for what I have. Sticking to 5.56 and 7.62x51; with some 7.62x39 and 6.5 creedmoor.
 
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Sig is apparently releasing the Spear (not the limited edition version that was released a while back) in .277 and there will be a new Cross in .277 as well, within the year (from Sig's own mouth, see vid below). Pressure has been lowered to 70,000psi and the Cross barrels are being nitrided to prevent premature wear. I guess it's fairly accelerated on a straight up untreated stainless barrel.

Accuracy and lifespan were the reasons for lowering the pressure.

 
That’s the video. If you go to 17:15, that’s where he explains them backing off of 80ksi to 70ksi, barrel steels, processes, and barrel life measured in a certain mv and accuracy range.
 
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I don’t think many, or any, manufactures are going to support the .277 Fury in the AR-10 platform. Why would they given the increased liability? There might be bolt heads and extensions out there that can handle the pressure, but it sounds like a lose-lose proposition for companies to offer a barrel on a platform it was never designed for.

edited to add - handling the pressure for a dozen or even a couple of hundred rounds doesn’t mean it’s safe over a lifetime.
 
Yes, I read they lowered the pressure to around 70,000 psi for better accuracy and barrel life. They are being used in full auto military weapons.
But the high pressure loading isn't dead.
Interesting video from the Ultimate Reloader, "308 W 300 WM velocities do not do this at home." Check out this video, where their two companies reps running the 308W to over 100,000 psi.
Do Not Do it...really. but they used a BAT action and new Alpha brass.
And for those interested with common sense and good reloading skills one can use the 6.8 X 51 hybrid brass for the 308, 6.5 CM, 8.6 Blackout, 358 Win and improve the velocity of any cartridge based on the 308 case head with shorter or similar COAL. And ya don't need 80,000 psi for an improvement. But neck turning and annealing are needed.
 

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