SIG Offering Army 6.8 Round to the Public - .277 Fury

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Bartholomew Roberts

Moderator
The Army is currently pursuing a new 6.8 round in experimental testing and there are three different companies chosen for competition for the Next Generation Rifle and Light Machinegun. The Army has required a specific 6.8mm EPR projectile (basically a 6.8mm version of the projectile used in M855A1) and set some classified performance requirements for it.

(Past discussion of Army solicitation and caliber: https://thefiringline.com/forums/showthread.php?t=602725)

SIG is announcing a new bolt-action rifle in a caliber they call “.277 Fury” which uses the same bimetallic case SIG is using in the Army trials. SIG is stating they are getting 3,000fps out of a 16” barrel with a 6.8mm bullet of unspecified weight.

http://soldiersystems.net/2019/12/1...-bolt-gun-and-caliber-sig-cross-277-sig-fury/
 
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The 7.62x51 has much more recoil than 5.56, which made it difficult to deliver rounds accurately in automatic fire. I think the 6.8 caliber bullet was a compromise between the two.
 
Both the 7.62X51 and the M14 were failed experiments as general purpose military rounds. The 7.62 round has it's place as a designated marksman round or as a short range snipers round. But the 5.56 we have been using for the last 50 years is just fine for most situations.

No cartridge nor platform to fire it from is perfect in every situation, but I'm certain we'd have filled more body bags in the last 50 years if we'd stayed with the 7.62 round.

It maybe possible to develop something in 26 or 27 caliber that improves on 5.56 without the negatives of 308. But I have serious doubts. In order to get the muzzle velocity with bullets they want to use you're going to have to very serious negatives. The laws of physics are strictly enforced, there is no way around it

#1 That much velocity, with that much bullet weight, from an AR 15 platform is going to generate as much, of not more recoil than you'd get from the much heavier M14/308 combo. Reducing recoil was a big part of the decision to drop the 7.62 round.

#2 To get the desired velocity is going to require light for caliber, short stubby bullets. While the MV looks good, that type bullet will lose velocity quickly limiting long range effectiveness. It also means poor penetration, especially on barriers. Those were 2 alleged negatives of the 5.56 round.

Unless the military had developed some type of mystery round that defies the laws of physics I don't see any advantage with any of the 6.5 or 6.8 cartridges that can't be solved by 70-77 gr bullets in the 5.56.
 
"...the 7.62X51 and the M14 were failed experiments..." The latter exists due to the former. Although it might be the other way. Both were American ideas at a time when everybody was working on a smaller calibre cartridge for use in Europe.
The .280 Enfield, for example. Basically a 7mm designed specifically for European battle fields. The U.S., however decided the 7.62x51 would be the NATO cartridge and threatened to leave NATO if it wasn't adopted.
 
We’ve got multiple threads on the military trials. I’d really appreciate people who want to rehash those arguments taking them there.

SIG offering their cutting edge technology to the public before the military trials are even done surprises me. Historically, that’s a move made by companies that lose the military trials.

I’ve got to say a 6.2lb rifle with the handling of a 16” barrel and the ballistics of a 24” .270 Win Mag sounds interesting. Seems like it would be a handy mountain rifle.
 
Bartholomew Roberts said:
We’ve got multiple threads on the military trials. I’d really appreciate people who want to rehash those arguments taking them there.

SIG offering their cutting edge technology to the public before the military trials are even done surprises me. Historically, that’s a move made by companies that lose the military trials.

I’ve got to say a 6.2lb rifle with the handling of a 16” barrel and the ballistics of a 24” .270 Win Mag sounds interesting. Seems like it would be a handy mountain rifle.
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I keep seeing the ballistics of this new 6.8mm round thrown around, and all I can think is how bad the muzzle blast and recoil must be. Unless they're using some special barrel steel of alloyed unobtanium and unicorn horn, I expect very, very short service life.

Really curious to see what these end up looking like in the wild. SIG has some flat out neat stuff, I'm just skeptical of their general ability to execute on scale.

Sent from my SM-A102U using Tapatalk
 
Well, you’ve got a good point P-990. You can introduce a fancy bimetallic cartridge that lets you accelerate a .277 bullet to 3,000 fps in a 16” barrel; but how long does that barrel last?

The link in my original post shows an “influencer” shooting the CROSS rifle in .277 Fury and he looks a little surprised at the recoil based on the muzzle jump in that first shot. He has it tamed by the second shot; but I’m guessing that guy is not a dirt clod shooter and he looked a bit shocked at first.
 
It maybe possible to develop something in 26 or 27 caliber that improves on 5.56 without the negatives of 308. But I have serious doubts. In order to get the muzzle velocity with bullets they want to use you're going to have to very serious negatives. The laws of physics are strictly enforced, there is no way around it
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Much like the 6.5 CM or Lapua that stays supersonic out past 1000 yards. Yep, a real downer.
 
Bartholomew Roberts said:
The link in my original post shows an “influencer” shooting the CROSS rifle in .277 Fury and he looks a little surprised at the recoil based on the muzzle jump in that first shot. He has it tamed by the second shot; but I’m guessing that guy is not a dirt clod shooter and he looked a bit shocked at first.
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I was a little surprised as well how much the muzzle jumped as well with that first shot. Considering that the rifle as equipped probably weighs 10+ lbs.

6.5 lbs Cross Rifle
31 oz Tango 6 rifle scope
15 oz Sig 762 DT suppressor

That puts you right at 9.5 lbs and you can probably add at least another .5 lbs for rings and ammo. As equipped in the article blows your mountain rifle theory out of the water.

The Cross rifle is a blatant copy of Q's Fix rifle, but I'm surprised someone didn't copy it sooner. I'm interested in the cartridge because I'm an unabashed .270 Win fan. I'd really like to know what bullet they were shooting, I'd also assume it's running pretty high pressure so I wonder about throat life.
 
More info on the civilian cartridge... 80,000 PSI!

This added pressure will drive a 135-grain bullet from SIG’s Hybrid Match cartridge 3,000 fps from a 16-inch barrel, and produce 2,694 ft.-lbs. of energy. The 135-grain bullet has a respectable .488 G1 BC.

SIG’s 277 Fury Hybrid Hunting load features a 140-grain bullet with a .508 G1 BC, launching from a 16-inch barrel at 2,950 fps. That one produces 2,706 ft.-lbs. of muzzle energy, too.
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https://www.tactical-life.com/gear/ammo/277-sig-fury-hybrid-case-design/
 
I’m thinking throat life is pretty poor but that AR style barrel extension will come in handy. Given some of the hiccups SIG has had with introducing new designs, 80k PSI makes me hope they ironed this out thoroughly.
 
If I am hunting bongo in the Congo, I am not worrying about barrel life, but if I am equipping a sizeable military outfit, it is going to be a logistic and budget problem.
 
I wonder what Jeff Cooper would think about this rifle/caliber combo since it checks off several of his boxes for the Scout rifle as far as length, weight, power, etc.
 
New info on the cartridge from Guns America: https://www.gunsamerica.com/digest/277-sig-fury-demystified/

The highlights are:
1. SIG plans to offer the ammo in 2020.
2. SIG is also going to offer other calibers, including long-action and a 6.5 that is not a Creedmoor using their bimetallic cases and proprietary powders.
3. The bimetallic cases will be reloadable.
4. SIG states they are “all-in” and will support this in the civilian market whether they win the military contract or not.
5. SIG claims their proprietary powder addresses the barrel life issue all of us are thinking about and while they won’t release numbers yet, it is going to be magical.
 
Bartholomew Roberts said:
New info on the cartridge from Guns America: https://www.gunsamerica.com/digest/277-sig-fury-demystified/



The highlights are:

1. SIG plans to offer the ammo in 2020.

2. SIG is also going to offer other calibers, including long-action and a 6.5 that is not a Creedmoor using their bimetallic cases and proprietary powders.

3. The bimetallic cases will be reloadable.

4. SIG states they are “all-in” and will support this in the civilian market whether they win the military contract or not.

5. SIG claims their proprietary powder addresses the barrel life issue all of us are thinking about and while they won’t release numbers yet, it is going to be magical.
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OK, I'm really curious what the proprietary special powder is going to do. Unless I'm completely mistaken, the primary issue with barrel life is mostly tied to gas pressure and temperature, which can roughly correlate with operating pressure. A combination of fast-twist barrel and obscenely high operating pressure should present a fairly short service life, no matter the secret sauce in the powder technology.

Now, back to the recoil and blast, I noticed the shooter's reaction in the video link. I also noticed the sample rifle is suppressed, which 99.9% of the rifles that end up in the wild won't be. Given the current trend toward milder, more shooter-friendly cartridges, this looks like a step back into the Magnum race of the '90s and early 2000s.

I don't want to hate on it until it's in the hands of the public, but I'm reading SIG as a lot of hype and hyperbole at this moment. Hopefully I'm completely off-base and it's a revolution in small-arms technology. Only time will shake that out.

Sent from my SM-A102U using Tapatalk
 
I'm reading SIG as a lot of hype and hyperbole at this moment.
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Probably a safe bet given SIG’s marketing methods and the fact that these are all basically press releases. Still, interesting to see SIG talk some hard numbers, although barrel life isn’t one of them yet.
 
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