[ManxumFoe]

First cup of morning coffee has kicked in and here is a thought that floated to the top:

So there is this new cartridge adopted for front-line combat troops, intended to replace the 5.56 NATO round (and the M-4). It has a heavier, low drag bullet, high velocity and a very high chamber pressure. The idea is to have a round that is lethal at 500 yards/meters and beyond. Yeah, they have re-invented the 30-04 and .300 Win Mag, but it is what it is.

So I got to thinking a bit. The Garand/M-14 actions can be adapted for cartridges with more umph such as .300 Win Magh and even .458 Mag . . .as I have read. Can the M-14 platform be adapted to this new round? The Amary rifle selected to fire the new round has a 15" barrel. The longer barrel of the M-14/M1A could push the .277 out there at a higher MV enhancing range and lethality. The M1A SOCOM-16 configuration would reproduce the balistics of the new issue gun.

What would it take to re-engineer and adapt the M-14 platform to deal with the new round's 80,000 PSI chamber pressure?

 

[lysander]

Start with a blank sheet of paper.

 

[Coop44]

I would think it would not be an alternative I would think of as viable. But if it's what you want have at it. The 277 is likely going to be a barrel burner given the numbers. Personally I have been considering the 243, widely avaialable, good numbers, flat shooter but also a barrel burner. A good choice for hunting, from varmint to whitetail deer, just use different bullet weight. Until it is out in the field being used, will remain a skeptic on the 277.
But to each his own.

 

[thehun06]

It won’t be a M14 rifle…I just don’t see the current M14 receiver being able to take such pressures…but who knows.

M14/M1A is quite “clunky”

 

[DetroitMan]

I don't see it happening. The proof load for 7.62mm NATO is 75,600 PSI. Service ammunition is supposed to be no more than 60,200 PSI. (Rough figures, thank you Wikipedia.) I am not an engineer. I would speculate that you could build an M14 pattern rifle, with the barrel and bolt made from high strength (expensive) steel, to withstand the pressure. You would then have to re-engineer the gas system to deal with the pressure.

If you want 3,000 FPS from the M14, you can get there with the 6.5 Creedmore. It can give you 9/10ths or better of the .277 Fury, but never 100%. However, it is sensitive to barrel length, so you would have to do it in a 22" M14. Velocity would go down in a SOCOM.

 

[Allen Humphrey]

The receiver ring and a heavy barrel could probably manage. That left lug….not so much.

 

[Grizzman]

I recall reading somewhere that there will be a "commercial" loading for the .277 Fury with a maximum pressure of 65,000 psi that does not use the stainless/brass hybrid case. I wouldn't be surprised if the 80,000 psi loadings are only available for the .mil.

With the use of an adjustable gas plug, I don't see why .277 Fury loaded to 65,000 psi wouldn't be feasible in my M14 clone. I also don't see much of a benefit, since 6.5 Creedmoor has already been proven to work.

 

[Random Guy]

Start with a blank sheet of paper.

I think that is the correct answer, and I will only add this as to the technical requirement or “why” the US Army developed the high pressure 6.8x51mm cartridge for their new light machine gun:

“I don’t always shoot a rifle at 1200 yards, but when I do, I prefer to use a precision bolt action rifle, preferably in caliber 6.5 Creedmoor.”

 

[lysander]

I recall reading somewhere that there will be a "commercial" loading for the .277 Fury with a maximum pressure of 65,000 psi that does not use the stainless/brass hybrid case. I wouldn't be surprised if the 80,000 psi loadings are only available for the .mil.

With the use of an adjustable gas plug, I don't see why .277 Fury loaded to 65,000 psi wouldn't be feasible in my M14 clone. I also don't see much of a benefit, since 6.5 Creedmoor has already been proven to work.

Continuous shooting of proof load level pressures in an M14 would not be recommended.

 

[ManxumFoe]

Start with a blank sheet of paper.

A good point.

Of course, that is the best plan and is what Big Army did. I was thinking of the folks on these forums who get into building their guns.

The Army's rifle will; not be available in a civilian legal version for a few yeaers I'll bet, so thinking about how to dit-'er-dun is something to look at.

 

[Grizzman]

I didn't phrase my previous post very well. I recall reading that the commercial .277 Fury cartridge will be loaded to a level that does not exceed 65,000 psi.....not that it will be loaded to 65,000 psi. Since this ammo doesn't seem to exist yet, it is completely unknown what pressure it will generate.

 

[ManxumFoe]

I don't see it happening. The proof load for 7.62mm NATO is 75,600 PSI. Service ammunition is supposed to be no more than 60,200 PSI. (Rough figures, thank you Wikipedia.) I am not an engineer. I would speculate that you could build an M14 pattern rifle, with the barrel and bolt made from high strength (expensive) steel, to withstand the pressure. You would then have to re-engineer the gas system to deal with the pressure.

If you want 3,000 FPS from the M14, you can get there with the 6.5 Creedmore. It can give you 9/10ths or better of the .277 Fury, but never 100%. However, it is sensitive to barrel length, so you would have to do it in a 22" M14. Velocity would go down in a SOCOM.

I don't know the engineering end of it either. Yet the barrel burner part has (somehow) been delt with by SIG, the selected manufacturer. The adopted rifle has a barrel under 16 inches, so a SOCOM-16 length M-14 could work too, given that the pressure issues have been worked out. A conventional M-1q4 barrel length could make it a screamer. Maybe Shuff can figure out a Mini-G rife in .277 Fury.

Putting together a .277 Fury project gun might be easier to do if starting with an M-10 size platform. The parts to be re-engineered would be the bolt, barrel, gas block and tube. I am guessing that some parts outfit will eventually put together a kit, if it can be done at all. Maybe it will be done by some muffler shop in Kyiv.
Probably, the first civilian legal rifle to be chambered for the high-pressure military round will be done by a gunsmith using a Mauser action I am guessing.

 

[WichitaWrat]

While the M14 couldn't withstand .277Fury, something could easily be built that would and it could be made to distinctly resemble an M14. But there would be a lot of machining involved. A little more material here and there. A project to be sure, but certainly not impossible.

What i find most fascinating is the overall history. Not quite a CENTURY ago, the Garand started its prototyping life as a .270 bullpup. While the Army is still not ready for a bullpup, here we are back at .270 again.

 

[Random Guy]

….if some collector has the money, here’s the limited production civilian version. It’s an SBR due to 13” barrel (not sure if suppressor included, but I’d consider it an absolute requirement with this rifle):

MCX-SPEAR

First Production Run Special Edition Now Available at Select Dealers MSRP: $7999.00

www.sigsauer.com

MCX-SPEAR
First Production Run Special Edition
Now Available at Select Dealers
MSRP: $7999.00

…but for 1/4 the cost, you can get an M1A in 6.5 Creedmoor that will provide similar long range performance well past 308W ballistics, but with much less expensive 140-147 grain match ammo that won’t burn out the barrel.

M1A™ Loaded Precision 6.5 Creedmoor Rifle - Springfield Armory

www.springfield-armory.com

As previously noted, I doubt we will ever see an aftermarket M1A barrel in 277 Fury unless its a custom one-off $$ barrel, but without a nitrated or chrome plated bore it would not make sense to me - moreover, getting the gas port diameter correct might require lots of test barrels and carefully controlled experimentation with laboratory equipment that can accurately measure port pressure. IMO, the initial $100k costs in engineering and laboratory testing would greatly exceed the tiny market share for such a niche M1A barrel. (Never mind the liability angle). So realistically it’s 308W or 6.5 CM calibers for the foreseeable future, but even 6.5 CM M14 barrels are quite scarce at this point.

(A bolt action barrel in 277 seems much more likely).

 

[Coop44]

I don't know the engineering end of it either. Yet the barrel burner part has (somehow) been delt with by SIG, the selected manufacturer. The adopted rifle has a barrel under 16 inches, so a SOCOM-16 length M-14 could work too, given that the pressure issues have been worked out. A conventional M-1q4 barrel length could make it a screamer. Maybe Shuff can figure out a Mini-G rife in .277 Fury.

Putting together a .277 Fury project gun might be easier to do if starting with an M-10 size platform. The parts to be re-engineered would be the bolt, barrel, gas block and tube. I am guessing that some parts outfit will eventually put together a kit, if it can be done at all. Maybe it will be done by some muffler shop in Kyiv.
Probably, the first civilian legal rifle to be chambered for the high-pressure military round will be done by a gunsmith using a Mauser action I am guessing.

A weatherby MK V action would be more than capable, one of the 6 lug bolt actions built for standard calibers like '06. But, I am a huge Weatherby fan.

 

[DetroitMan]

I don't know the engineering end of it either. Yet the barrel burner part has (somehow) been delt with by SIG, the selected manufacturer. The adopted rifle has a barrel under 16 inches, so a SOCOM-16 length M-14 could work too, given that the pressure issues have been worked out. A conventional M-1q4 barrel length could make it a screamer. Maybe Shuff can figure out a Mini-G rife in .277 Fury.

Putting together a .277 Fury project gun might be easier to do if starting with an M-10 size platform. The parts to be re-engineered would be the bolt, barrel, gas block and tube. I am guessing that some parts outfit will eventually put together a kit, if it can be done at all. Maybe it will be done by some muffler shop in Kyiv.
Probably, the first civilian legal rifle to be chambered for the high-pressure military round will be done by a gunsmith using a Mauser action I am guessing.

So far the only measure I have heard SIG has taken to address the barrel burner issue is that the barrel and gas system are quickly replaceable. I am phrasing it that way partially to be funny, but I have not heard of anything else. So if you have heard of something that I haven't, please share. I know that chrome lining and other bore coatings will increase barrel life, but I have not heard specifics of how SIG is treating the barrels.

It has also been reported that the military is procuring reduced pressure rounds (i.e, something in the "normal" range of cartridges today) in addition to the 80k loads. There is lots of speculation about why this might be, but barrel life extension is a plausible reason, even if there are multiple reasons for it.

For these reasons I am not convinced that the issue is dealt with. It may be, but I like to know details on things before I accept claims. I am interested in the .277 Fury cartridge and watching the news on development.

EDIT: As far as getting our hands on it, you can bet that SIG plans to introduce the MCX Spear to the civilian market as soon as their production can exceed the demand for the military contract.

 

[ManxumFoe]

If Big Army is only addressing the barrel-life/bore-wear issue with a quick-change approach and buying lower pressure loadings . . .why not just go to a "standard" or existing magnum cartridge? If the job can be done with off the shelf chamberings and platforms . . .I mean, JEEPERS (substitute a bad word here), They just committed to10 years of spending billions of dollars on thousands of rifles.

So then, as someone else on this thread has opined, they really were looking for a problem to solve.

 

[ManxumFoe]

And now looking for the silver lining in the un-intended consequences:

The civilian shooting world may get another cartridge to play with and optimize for sport shooting.

We may also get a legal to own computerized sighting aid that costs less than the down payment on a Bently.

 

[Coop44]

And now looking for the silver lining in the un-intended consequences:

The civilian shooting world may get another cartridge to play with and optimize for sport shooting.

We may also get a legal to own computerized sighting aid that costs less than the down payment on a Bently.

Don't you all have enough cartridges and electronic doodads to play with already? I only have time a not enough money to play with a handful of them now! As far as gee whiz electronic crap, what is going to make hitting a paper target easier?

 

[DetroitMan]

If Big Army is only addressing the barrel-life/bore-wear issue with a quick-change approach and buying lower pressure loadings . . .why not just go to a "standard" or existing magnum cartridge? If the job can be done with off the shelf chamberings and platforms . . .I mean, JEEPERS (substitute a bad word here), They just committed to10 years of spending billions of dollars on thousands of rifles.

So then, as someone else on this thread has opined, they really were looking for a problem to solve.

Garand Thumb released a video on the MCX Spear, and he brought up an interesting point. The Army adopted the M855A1 round for the M4 / M16, which is a hot load. They accepted a 10,000 to 12,000 round barrel life in order to get that round. So there is a good argument that barrel life is no longer a primary concern for them.

The Army is always looking overmatch potential threats. I do think that there are good arguments for replacing the 5.56 NATO. I also think that the .277 Fury might be overkill for that. I think it has a lot of potential, but it may be too much to give every soldier when you factor in the increased loadout weight, reduced ammunition capacity, etc. A cartridge moderately more powerful than the 5.56 might have been a wiser choice. Time will tell.