.277 SIG Fury (6.8x51mm) - .270 WCF Performance from a 16" Bbl.

[Gtscotty]

Well...

If the use quicker powder to generate 1/3 higher chamber pressure, for a 1/3 shorter barrel...?

The muzzle pressure might be similar.

Like a HG round out of a carbine.


I think that the milspec calls for a suppressor.

One of the articles said that Sig has been working with some new powder blends optimized for this case, I'm guessing that they are denser then usual because playing with Quickload, you could reach the performance levels they were indicating with 80 ksi pressures, a 60gr case capacity and existing powders, but most loads were pretty compressed.

In general, what you said seemed to be true, at least while just doodling with Quickload. Faster than normal powders gave the highest velocities at 80 ksi because the slower powders were too dense to pack enough in. With these faster powders, the muzzle pressure was lower than you'd think, and lower in general than big magnum cases using heavy loads of slow burning powder at normal MAP.

In general though, I still think a 16" lightweight threaded hunting rifle like this is probably intended for suppressed use, in which case the muzzle pressure/blast is of little concern (as long as your can is rated for it).

 

[NR53]

I wonder what they've used for primers in this cartridge? 80K psi is a lot of pressure! I would certainly think they would have to be crimped in place. I've blown conventional primers with a lot less pressure.

 

[denton]

My first reaction was.....

Rebarrel

Sight in

Rebarrel

Sight in..

 

[Texas10mm]

My first reaction was.....

Rebarrel

Sight in

Rebarrel

Sight in..

Barrel life has to be under 1K rounds. That's a hell of a burden on the military.

 

[Gtscotty]

Barrel life has to be under 1K rounds. That's a hell of a burden on the military.

Don't you think the Army has accurate barrel life objectives and thresholds that the offerors will be rated against? The .mil does some stupid stuff, but not that stupid, I'm 110% certain there is a requirement for barrel life in the NGSW.

If you haven't been involved with a DOD solicitation before, the offerors don't make those kinds of decisions. The Army decides what it wants and can live with and lays these out in the form of requirements that the offeror's submissions either meet or don't. Besides, I don't think it would be that low, even without the various coatings and materials they will use to extend life. <60gr of powder through a .277 diameter bore, 15 ksi higher at the case neck than the .270, but dropping off faster than a larger load of magnum powder would.

 

[adcoch1]

Phew! Is it for anti personal or game? Does anybody need it? I don't want that type of new pressure jump next to my face. JMO
PS I don't want a 2 piece case with a seam to fail at the head.

I would bet that is just a steel sleeve at the case head to help limit deformation. Remember that a lot of proof loads for modern guns are over 80k pressure in brass. This will probably be tough on barrels, and tolerances will probably be tighter than some guns, but the Idea has some merit. But yeah, the fireball at the muzzle! Gonna pass myself.

 

[js8588]

Will watch with interest. This has potential to be the next big thing in firearm technology development. Because Sig USA is the driving force behind it, this has the potential to go spectacularly wrong.

 

[Texas10mm]

Don't you think the Army has accurate barrel life objectives and thresholds that the offerors will be rated against? The .mil does some stupid stuff, but not that stupid, I'm 110% certain there is a requirement for barrel life in the NGSW.

If you haven't been involved with a DOD solicitation before, the offerors don't make those kinds of decisions. The Army decides what it wants and can live with and lays these out in the form of requirements that the offeror's submissions either meet or don't. Besides, I don't think it would be that low, even without the various coatings and materials they will use to extend life. <60gr of powder through a .277 diameter bore, 15 ksi higher at the case neck than the .270, but dropping off faster than a larger load of magnum powder would.

There's barrel life and then there's accurate barrel life. Accurate barrel life is going to be around 1000-1250 rounds. Some of the PRS long range guys using the big cases are replacing barrels before that because of lost accuracy.

 

[someguy2800]

I would bet an accurate barrel life of 2000 rounds in a bolt action. Decently large bore size for the powder capacity.

 

[Gtscotty]

There's barrel life and then there's accurate barrel life. Accurate barrel life is going to be around 1000-1250 rounds. Some of the PRS long range guys using the big cases are replacing barrels before that because of lost accuracy.

That's why I specified accurate barrel life. The Army will have specified objectives and thresholds for accurate barrel life, along with what qualifies as accurate. The truth is no one here really knows enough about this brand new cartridge for all these prognostications on what barrel life will or won't be to have any meaning. What is the case capacity? What powders are being used? How does barrel damage in a .277 bore scale between MAPs of 65 ksi and 80 ksi? What materials are the NGSW barrels made of, and what coatings or treatments are being used. Without any of this basic information, it's all just hand waving.

I would bet an accurate barrel life of 2000 rounds in a bolt action. Decently large bore size for the powder capacity.

If I'm to join in the hand waving, I'd probably guess about the same. The closest analog would probably be the 7mm-08AI. Bumping the MAP up another 18 ksi to 20 ksi is probably going to knock down the accurate barrel life. From 3k-4k to 2k sounds about as good as any other guess here, ignoring barrel coatings of course, something like nitriding is going to have a significant impact.

The only reviewer I've heard mention barrel life said that Sig was still finalizing the numbers, but the preliminary numbers they gave him were "better than you're thinking". Under 1k is not going to be better than anyone is thinking, ~2k would probably qualify though.

 

[Jim Watson]

2000 would be amazing Super powder, super barrel material.
When I was shooting F class, the Army team was replacing 6.5-284 barrels at 850.
Shooters paying for their own were going 1200, hoping for 1400.

 

[Orcon]

Man are these folks gonna be mad when they find out about the 270 WSM.

 

[Garandimal]

Man are these folks gonna be mad when they find out about the 270 WSM.

Magnum case head diameter, 10 grains more powder, fewer/heavier cartridges/mag/load-out, and a terrific muzzle blast out of a 16" Bbl..

So, probably not.




GR

 

[Orcon]

Magnum case head diameter, 10 grains more powder, fewer/heavier cartridges/mag/load-out, and a terrific muzzle blast out of a 16" Bbl..

So, probably not.




GR

Muzzle blast is a false flag narative invented by the government to sell more supressors in order to service our outstanding national debt 200 bucks at a time.

All joking aside, with a chamber pressure of 80k psi do you have any doubts that muzzle blast would be any less than a 62k psi cartridge? Also, this cartridge is being pre-emptively released to the civilian population, Sig wouldnt be doing that if they thought this was a done deal. It's a combination of user-paid product testing and using the commercial sector to tamp down future losses when this thing flops.

 

[Jim Watson]

Every US military breechloader cartridge has been a success on the commercial market. I can STILL buy a .50-70, not to mention .45-70, .30-40, .30-06 (.30-03 might take a little work these days.) .308 and .223. Not as much done with .30 carbine short of surplus and copies, but not zero; even pistols. Not to mention offshoots like 6.8 and .300 boo.
Sig is just trying to join the parade.

Now the other contenders are further from commercialization, but plastic cases might sell to the non-reloader. Telescoped ammo is a ways out from the sportsman.

 

[Garandimal]

Muzzle blast is a false flag narative invented by the government to sell more supressors in order to service our outstanding national debt 200 bucks at a time.

All joking aside, with a chamber pressure of 80k psi do you have any doubts that muzzle blast would be any less than a 62k psi cartridge? Also, this cartridge is being pre-emptively released to the civilian population, Sig wouldnt be doing that if they thought this was a done deal. It's a combination of user-paid product testing and using the commercial sector to tamp down future losses when this thing flops.

Profiting on their R&D, regardless of adoption, seems like a prudent decision, especially since they mentioned that their design is re loadable, where the competition submissions are not.

80K psi will allow for the use of quicker powder, producing both velocity and cooler muzzle temperatures sooner.

A .270 WSM - would be a 4th of July pyrotechnic out of a 16" Bbl.




GR

 

[Llama Bob]

Increasing pressure is a very effective way to increase efficiency. However even if the rifle is strong enough, there are two big problems that kick in around 65KPSI:
1) Primers won't take it and deform/pierce.
2) The cases stick in the chamber as primary extraction can't overcome the friction.

The article does not appear to discuss what solution (if any) is offered for these two problems.

 

[Llama Bob]

A .270 WSM - would be a 4th of July pyrotechnic out of a 16" Bbl.

Nah, just a slight flash. QL shows 99.2% burned with Retumbo, which would be the highest veolcity powder. Performance is in-line with what Sig's claims.

This seems to have no performance edge over a .270 WSM, although it is smaller.

 

[Garandimal]

Increasing pressure is a very effective way to increase efficiency. However even if the rifle is strong enough, there are two big problems that kick in around 65KPSI:
1) Primers won't take it and deform/pierce.
2) The cases stick in the chamber as primary extraction can't overcome the friction.

The article does not appear to discuss what solution (if any) is offered for these two problems.
.

Well...

SIG has obviously overcome both those problems, as they have been accepted as a finalist in the procurement contest.

Would expect that the SS case head would have a lot to do w/ both.

Nah, just a slight flash. QL shows 99.2% burned with Retumbo, which would be the highest veolcity powder. Performance is in-line with what Sig's claims.

This seems to have no performance edge over a .270 WSM, although it is smaller.

IF - you can meet the performance spec out of a 16" Bbl. with the .270 WSM and Retumbo powder?

You will certainly not meet the weight and load-out specs., as the SIG round is a .308 cased round that is 50% lighter.

And then there is also the added recoil of ten extra grains of powder - on an already high-recoil round.




GR

 

[mjsdwash]

at 80k chamber erosion will be an issue, one not going to be solved with chrome, or nitrite, though some acronym or buzzphrase name for their "proprietary process" will make it sell. I do wonder if manufacturers are figuring out that shot out barrels are not a big issue for people who shoot 25 yards and pretend its 200. Those who shoot long range probably wont care anyway. What exactly is this going to do that a 7-08 wont do if your willing to load it to stupid pressures? Good luck to them.

 

[mikeone]

 

[Jim Watson]

See, all you have to do is neck down .308. That gives you a false shoulder to fireform from and Bob's your uncle. Just Quickload some 60,000 psi and nobody on the 100 yard range can tell a thing.

 

[Garandimal]

That's why I specified accurate barrel life. The Army will have specified objectives and thresholds for accurate barrel life, along with what qualifies as accurate. The truth is no one here really knows enough about this brand new cartridge for all these prognostications on what barrel life will or won't be to have any meaning. What is the case capacity? What powders are being used? How does barrel damage in a .277 bore scale between MAPs of 65 ksi and 80 ksi? What materials are the NGSW barrels made of, and what coatings or treatments are being used. Without any of this basic information, it's all just hand waving.



If I'm to join in the hand waving, I'd probably guess about the same. The closest analog would probably be the 7mm-08AI. Bumping the MAP up another 18 ksi to 20 ksi is probably going to knock down the accurate barrel life. From 3k-4k to 2k sounds about as good as any other guess here, ignoring barrel coatings of course, something like nitriding is going to have a significant impact.

The only reviewer I've heard mention barrel life said that Sig was still finalizing the numbers, but the preliminary numbers they gave him were "better than you're thinking". Under 1k is not going to be better than anyone is thinking, ~2k would probably qualify though.

Also good not to lose sight of the fact that, according to TC (FM) 3-22.9 "Rifle and Carbine"/ Appendex F/ "Qualification Standards"/ Qualification of individual Soldiers on the M16/M4 series rifle and carbine:

F- 16.
A KD range has two primary objectives:
(1)Fire tight shot groups (maximum 6.5 MOA) at a known distance.
(2)Make sight adjustments at range while experiencing the effects of wind and gravity.

​

The rifle/Carbine being a maximum 4.5 MOA itself.

So there's that.




GR

​

 

[Texas10mm]

View attachment 880854

What is this picture showing up?

 

[LoonWulf]

Nah, just a slight flash. QL shows 99.2% burned with Retumbo, which would be the highest veolcity powder. Performance is in-line with what Sig's claims.

This seems to have no performance edge over a .270 WSM, although it is smaller.

Ive never wanted a .270wsm till now, or a 16" barreled magnum.........I kinda wanna see if it will do it, and what it would be like.....time to start cruising gunbroker.