80,000 PSI capable actions for Sig Fury

[Noobilicious]

Sig Sauer is preparing to release its 277 Fury and 6mm Fury cartridges next year. These Fury cartridges operate at 80,000 PSI, and supposedly deliver two benefits for the sportsman:

1) Higher velocities from shorter barrels,
2) and more efficient cartridge (similar to how 65,000 psi Creedmoor PRC have dominated over older lower pressure cartridges)

Are there any actions on the market that can operate at these pressures?

 

[Milf Dots]

I'm sure Sig Sauer will be one of the first to have an action for it. Probably AI, Barrett, and Defiance, too.

 

[DDGKunia]

It's not the action, it's the brass that limits pressure. At least on a bolt gun. Sig is using a hybrid brass/steel cartridge to achieve those pressures.

 

[stello1001]

Hoplite Arms should have a bolt action rifle that while I don't remember the exact pressure it was tested to, I think could handle somewhere in the 100+ so there's that...

 

[6AYoteHunter]

In that bolt face size 700 clone actions will handle over 120k psi without lug setback. Blowing primers will be the interesting situation with hybrid cases in the future. I have seen blow primers hit the firing pin hard enough to bend it. If they go with stronger primers then the firing pin springs would have to be stronger which will affect the trigger adjustments.

 

[glock63]

Barrel life should be stellar, lol

 

[Barelstroker]

I'm not sure that it's got anything to do with the strength of the action perse. Rifle actions can be designed & built to handle much more than 65k or 80k or even 200k if need be.
As far as I've read, the powders we have access to are the limiting factor.
I've seen a bunch of pressure graphs taken with overloaded cases for testing purposes & what the graphs showed was the "knee" position in the powder burn cycle which, showed the combustion cycle moving from conflagration into detonation. This is primarily why we see usually significantly reduced pressures listed for relatively fast burning powders for any particular cartridge.
My understanding is that the "knee up" to detonation happens at lower pressures with relatively fast burning powders &, in order to ensure that hand loaders stay well away from the "knee" region, pressures must be reduced as a result.
My guess is that Sig are using different powder in order to achieve those higher pressures while maintaining the IB cycle within control limits.

 

[Cardboard Assassin]

Barrel life should be stellar, lol

I bet

Could be a good candidate for one of those Bartlein special steel long life barrels (40MODBB or whatever it is called).

 

[srt-4_uk]

I bet

Could be a good candidate for one of those Bartlein special steel long life barrels (40MODBB or whatever it is called).

Might even get to 800 rounds with it!

 

[Mech Eng]

The Bolt thrust would be that of like a hot 300 WM if the internal case head diameter is similar to a 308 win. Barrel life would be interesting because if they use a more efficient powder it might not be that bad, but testing will tell.

 

[softcock]

In that bolt face size 700 clone actions will handle over 120k psi without lug setback. Blowing primers will be the interesting situation with hybrid cases in the future. I have seen blow primers hit the firing pin hard enough to bend it. If they go with stronger primers then the firing pin springs would have to be stronger which will affect the trigger adjustments.

So if you buy a Sig Fury277 , it is some kin of hybrid proprietary/Sig cartridge your Married to ? , you have to by factory box ammo, and you cant reload ? Or only able to buy Brass from Sig. ? . . And I dont see the point ? , Bullets can only be pushed so far to the wall, So then you are limited to only shooting solids and no jackets ?
Sig must be using some kind of proprietary hybrid Brass with a super hard Case head ?
Not just primers blown, or pockets being blown-out after the 1st firing . But there be a crapload of Brass flow all over your Bolt Face, and flow into Fire Pin Boltface hole .
.

 

[brazz04]

This is what was released way back when it was being talked about. Just an idea of what the design was

 

[BadAccountant]

I remember reading about the proof testing of a Remington action. It was tested up to 110,000 PSI without failing when the researchers decided to stop.

Actions are stupidly strong.

I would think the limiting factor is the diameter and support the bolt head provides around the cartridge base and the cartridge design itself.

The brass is the more immediate problem, which is why the stainless base was introduced.

 

[4O6shootist]

I believe Bat Machine tested the vampire/bumblebee actions up to obscene pressure, like 170k psi? Bat makes an excellent action.

 

[Makinchips208]

The 3 piece cartridge case from Sig is a very clever design! Hats off to them for innovating anyways.

 

[srt-4_uk]

Why develop a new cartridge when you can just put 44 grains of Varget in a 22 Creedmoor?

 

[Midpack]

Why develop a new cartridge when you can just put 44 grains of Varget in a 22 Creedmoor?

But that's only for if you are a "proficient reloader"

 

[acudaowner]

all parts made and assembled in a Chinese sweatshop that use only the highest quality slave labor , I am still holding out for the elon musk version of hi tech guns that use an ammo that's fueled instead of powder but smug it will smell like burning hair and cabbage when fired but no more will powder or primers be needed the guns will look like lasers from star trek and will distort matter around it in some way so every shot hits the exact same pinhead as the shot before it making practicing needless thus destroying the whole industry
.

 

[Makinchips208]

all parts made and assembled in a Chinese sweatshop that use only the highest quality slave labor ,

The sig cross is?

 

[Dead Eye Dick]

I’m gonna stick my nose into this discussion. What’s the point? If one really needs more power, get a bigger gun. Why supercharge a 270 caliber bullet when a .300 or a .338 would do the same job at more reasonable pressures. Heck, one can do things with a .35 Whelen that make it as pleasant as a .243 for light stuff and almost stout enough (maybe not almost, maybe just plain stout enough) to take down Cape Buffalo. (Right bullet, right powder, right reloader.)

 

[meestermurphy]

They definitely aren't made in a Chinese sweatshop.

It's Sig, so they are made in India along with their other small parts. The curry makes the brass extra spicy!

 

[brazz04]

I’m gonna stick my nose into this discussion. What’s the point? If one really needs more power, get a bigger gun. Why supercharge a 270 caliber bullet when a .300 or a .338 would do the same job at more reasonable pressures. Heck, one can do things with a .35 Whelen that make it as pleasant as a .243 for light stuff and almost stout enough (maybe not almost, maybe just plain stout enough) to take down Cape Buffalo. (Right bullet, right powder, right reloader.)

What do you have against a 130gr bullet going 3000fps out of a 16" barrel? That sounds mighty handy when out hunting. I think the point is literally not getting a bigger gun.

 

[Dogtown]

"Mo fasta boolet, mo stronga recoil"

 

[srt-4_uk]

Gun guys: there's no innovation in the industry. Everything has been done

*Actual innovation*

Also gun guys: Its just a solution looking for a problem. It cost more than something that we've used for decades.

 

[762 ULTRAMAGA]

What do you have against a 130gr bullet going 3000fps out of a 16" barrel? That sounds mighty handy when out hunting. I think the point is literally not getting a bigger gun.

I'm already sending 144 bergers at 2925 from my 16" 6.5 saum
So yeah I think the short barreled high velocity solution is covered.. Get a bigger case

 

[srt-4_uk]

Now apply that same 277 Fury principles to something SAUM sized. And then in long action. Then long action magnum.
It's a proof of concept, not an end goal.

 

[brazz04]

I'm already sending 144 bergers at 2925 from my 16" 6.5 saum
So yeah I think the short barreled high velocity solution is covered.. Get a bigger case

More than one way to accomplish everything. Again, nothing wrong with options.

 

[762 ULTRAMAGA]

Totally
I'm just saying it's much cheaper and easier to go with a saum or wsm for equal or better results than the 277 fury.
Not that I'm against the innovation but it'll have to really come down in price before I get excited

 

[ormandj]

You have to keep in mind the intended military market. Ammunition weight is a huge deal. Try hiking around with a combat load (210 rounds) of 338 whatever mentioned earlier; that's going to be a TON of fun. Higher pressure, smaller case, lighter bullets. It's not something I'm likely to pick up, but it's not completely ridiculous either. I don't tend to run around packing 7x30rd magazines, either.

 

[Satterlee]

What will an all-steel case hold for pressure? or is that just not clever enough.

 

[4O6shootist]

What will an all-steel case hold for pressure? or is that just not clever enough.

Reload some wolf or tula and let us know!

 

[762 ULTRAMAGA]

Good point
Gonna run my ar-47 @80,000psi and send 123 fmjs 3200 fps

 

[Feniks Technologies]

Steel cases have extraction issues and such.

Which is why it’s a challenge for HP ammo. Brass doesn’t like that kind of pressure and steel has other issues.

 

[DeathBeforeDismount]

Totally
I'm just saying it's much cheaper and easier to go with a saum or wsm for equal or better results than the 277 fury.
Not that I'm against the innovation but it'll have to really come down in price before I get excited

Its not being compared or competing against a SAUM or WSM.

Take that same principle and apply it to a SAUM or WSM case and now run them at 80K PSI

Get it now?

 

[LG65CM]

So if you buy a Sig Fury277 , it is some kin of hybrid proprietary/Sig cartridge your Married to ? , you have to by factory box ammo, and you cant reload ? Or only able to buy Brass from Sig. ? . . And I dont see the point ? , Bullets can only be pushed so far to the wall, So then you are limited to only shooting solids and no jackets ?
Sig must be using some kind of proprietary hybrid Brass with a super hard Case head ?
Not just primers blown, or pockets being blown-out after the 1st firing . But there be a crapload of Brass flow all over your Bolt Face, and flow into Fire Pin Boltface hole .
.

Good questions and points. lg

 

[762 ULTRAMAGA]

Its not being compared or competing against a SAUM or WSM.

Take that same principle and apply it to a SAUM or WSM case and now run them at 80K PSI

Get it now?

No shit dude
My point is that if one wants that performance and then some from a 16" barrel it exists at a fraction of the cost

 

[Ledzep]

Kinda comical...

 

[DeathBeforeDismount]

No shit dude
My point is that if one wants that performance and then some from a 16" barrel it exists at a fraction of the cost

Not quite. You can't get the same performance because you cant get the same package.

You think people want WSM recoil out of their 8 Lb rifles? Where are these 16" 8lb semi auto WSM fighting guns at?

There is a huge difference between a higher pressure round and a much higher powder charge, not to mention form factor.

These were designed primarily for the military. Its not hard to understand the why.

 

[DeathBeforeDismount]

Sig initially designed the 277 fury for a belt fed machine gun. I have never ran a machine gun but this seems like its asking a lot out of a barrel.

Barrel is not the issue. Steel makes a great pressure vessel.

The issue is the casings. This is mostly due to Thermal Management. Brass while being very ductile and reasonably strong (But no where near steel for strength) is also a fantastic thermal conductor. When your fire, a lot of heat is created. To keep the barrel from quickly heating to the point its properties change, the brass absorbs this heat from the chamber and extracts it from the rifle. This also happens with steel, but steel has its own set of issues, its much less ductile which is why case head separation is the biggest issue.

That has been the main issue with these polymer/hybrid cases, It doesn't remove the heat from the chamber and has a habit of getting suck.

Most effort has been into telescoping case ammo in an effort to reduce the weight while increasing the pressure. They have the same issue with heat extraction which is the main reason no one actually fields them despite the tech being decades old. Cheaper to manufacture, lighter and easier to carry.

So far no one has really cracked it. Needs to be lighter, higher pressure, removes heat similarity and cheaper to produce. 3 is easy but all 4 is a real SOB.

 

[srt-4_uk]

Barrel is not the issue. Steel makes a great pressure vessel.

The issue is the casings. This is mostly due to Thermal Management. Brass while being very ductile and reasonably strong (But no where near steel for strength) is also a fantastic thermal conductor. When your fire, a lot of heat is created. To keep the barrel from quickly heating to the point its properties change, the brass absorbs this heat from the chamber and extracts it from the rifle. This also happens with steel, but steel has its own set of issues, its much less ductile which is why case head separation is the biggest issue.

That has been the main issue with these polymer/hybrid cases, It doesn't remove the heat from the chamber and has a habit of getting suck.

Most effort has been into telescoping case ammo in an effort to reduce the weight while increasing the pressure. They have the same issue with heat extraction which is the main reason no one actually fields them despite the tech being decades old. Cheaper to manufacture, lighter and easier to carry.

So far no one has really cracked it. Needs to be lighter, higher pressure, removes heat similarity and cheaper to produce. 3 is easy but all 4 is a real SOB.

Containing the pressure isn't what he's talking about. He's talking about surviving the heat from a string if fire.

Yes a traditional steel barrel is gonna be fucked. It's gonna glow with a quickness.

 

[WindstormSCR]

The origin behind this was simply to satisfy the NGSW requirements, and do so in a cartridge they could fit inside a standard large frame action.

the 277 fury case head is *exactly* the same as 6.5CM and .308W. the only difference is the shoulder and case mouth.

I've already got cad models drawn up for a rig to re-shape the brass back to 6.5 and .308 dimensions, because 300WM performance from a large frame semi action of suitable strength sounds fun to me!

some basic quickload tinkering shows this has the potential to (for example) allow an M110 style gasser to run bullets and MVs normally reserved for 300WM/300WSM

basically for bolt actions I don't think it offers much unless you really want to do something silly like running an ultralight short action with magnum-esque power, for semiautos it might be quite compelling

 

[Ledzep]

I sometimes wonder if the biggest hazard in pushing pressures any higher than is typical now has nothing to do with the hardware involved...

 

[DeathBeforeDismount]

Containing the pressure isn't what he's talking about. He's talking about surviving the heat from a string if fire.

Yes a traditional steel barrel is gonna be fucked. It's gonna glow with a quickness.

There are steel alloys that can probably handle this. High Nickel and other modern wonder alloys. They just haven't really been tested too much in this area but if they were the weakest link, that is where the development would be focused. It would not be hard to make them economically viable based on the scale they would be produced.

 

[Mech Eng]

Barrel is not the issue. Steel makes a great pressure vessel.

The issue is the casings. This is mostly due to Thermal Management. Brass while being very ductile and reasonably strong (But no where near steel for strength) is also a fantastic thermal conductor. When your fire, a lot of heat is created. To keep the barrel from quickly heating to the point its properties change, the brass absorbs this heat from the chamber and extracts it from the rifle. This also happens with steel, but steel has its own set of issues, its much less ductile which is why case head separation is the biggest issue.

That has been the main issue with these polymer/hybrid cases, It doesn't remove the heat from the chamber and has a habit of getting suck.

Most effort has been into telescoping case ammo in an effort to reduce the weight while increasing the pressure. They have the same issue with heat extraction which is the main reason no one actually fields them despite the tech being decades old. Cheaper to manufacture, lighter and easier to carry.

So far no one has really cracked it. Needs to be lighter, higher pressure, removes heat similarity and cheaper to produce. 3 is easy but all 4 is a real SOB.

When you say thermal management with this new hybrid case are you saying it's not going to work because the brass portion absorbs heat faster than the stainless during firing?

 

[DeathBeforeDismount]

When you say thermal management with this new hybrid case are you saying it's not going to work because the brass portion absorbs heat faster than the stainless during firing?

In essence yes. The brass removed heat from the chamber helping the barrel from cooking. Besides the barrel being heating to the point it loses strength, the heat alone will start cooking rounds off and you get a run away gun. This was common in machine guns with high cyclic rates and poor discipline. Thats why most MG's are 2 man teams with a gunner and an AG who manages the ammo and barrel swaps to keep the gun up.

It looks like only the casehead is stainless. I assume (and its been years since I took a metallurgy class) there is not enough thermal mass there to remove the same amount of heat as a brass case would. Yellow Brass has a little over 7 times the thermal conductivity of Stainless Steel. Those little cases are tremendous heat sinks.

 

[Mech Eng]

What I'm confused by is how the brass case would be cooler then the barrel after firing the round since the powder charge is burning inside the case.

 

[1moaoff]

What I want is a 2 stage propellant!

 

[z987k]

basically for bolt actions I don't think it offers much unless you really want to do something silly like running an ultralight short action with magnum-esque power, for semiautos it might be quite compelling

Ultalight short action with magnum esque power out of a 16" barrel and suppressed sounds like the ultimate hunting rifle.

 

[4O6shootist]

Ultalight short action with magnum esque power out of a 16" barrel and suppressed sounds like the ultimate hunting rifle.

The only problem is finding a supressor manufacturer that'll rate their can at that psi from a 16" barrel.

 

[z987k]

The only problem is finding a supressor manufacturer that'll rate their can at that psi from a 16" barrel.

Sig clearly does. Since they have videos of them running this round belt fed, full auto, suppressed.