.277 SIG Fury

[DiabeticKripple]

Interesting new cartridge I just found out about today. Designed for belt fed machine guns for the military, but SIG is going to be commercially producing it for the public as well.

Same case head as the .308 Win, similiar in OAL too.

3,000+FPS with a 140gr bullet out of a 19” barrel! 80,000psi is a lot of pressure.

Quite an interesting idea with the 3-piece casing too. Stainless steel at the bottom around the case head to withstand the higher pressures and make for more reloads per casing. It’s also lighter than just a brass casing.

https://www.gunsamerica.com/digest/2...y-demystified/

[CaberTosser]

That one looks like it will dictate some pretty strong actions to accommodate its pressure. I was catching some info on it as well. A squad machine gun firing 140 grain pills and that velocity will be interesting. Keeping the two piece cartridge together must have had a lot of thought put into its design, especially for something firing full-auto.

I’m curious what velocity a 24” or 26” barrel would achieve from that round? I imagine that throat erosion would certainly be a thing.

If a round left the muzzle at 3500 and hit flesh at 3250 or so it would change things. Also imagine the additional standoff capability versus an opponent firing rounds at 2350 FPS....

[amosfella]

Apparently, they've got special coatings in the barrel to keep the throat from eroding. I wonder if it's diamond like coating or similar that extend the life of carbide machining tools.

[FishOutOfWater]

https://www.youtube.com/watch?v=iOft-vaB0Jc

Sig also made a new bolt action rifle chambered in Sig Fury, as well as 308win & 6.5cm.

The commercial version (all brass case, less pressure) of the ammo is soon to be available, according to the author of the video above.

If you look closely though, the headstamp says 6.8 x 51mm...!

[elkhunter11]

Originally Posted by FishOutOfWater

https://www.youtube.com/watch?v=iOft-vaB0Jc

Sig also made a new bolt action rifle chambered in Sig Fury, as well as 308win & 6.5cm.

The commercial version (all brass case, less pressure) of the ammo is soon to be available, according to the author of the video above.

If you look closely though, the headstamp says 6.8 x 51mm...!

I wonder how long it will be, before some people without a clue try loading the all brass cases to the pressures meant for the composite case?

[Nyksta]

Unless the ammo cost is similar to 5.56, the longterm price of ammo will be the end of this idea.

[rembo]

That's a lot of pressure. Steel head cases are not new however.

http://cartridgecollectors.org/cmo/cmo10jun.htm

[Pathfinder76]

Originally Posted by elkhunter11

I wonder how long it will be, before some people without a clue try loading the all brass cases to the pressures meant for the composite case?

You must have grown up with, and worked around some real gems.

[CaberTosser]

I'd like to see a cross-section of the two-piece case to see how they are joined. I imagine they've tested extensively to ensure they don't get separated during full-auto fire, that would be a real bugger to have the brass section of it stuck in the chamber during combat, possibly with another round jammed in behind it where the bolt won't close.

[freeride]

interesting.

As a side point... With the bolt action gun in there too for civilians this should have the benefit of bringing a bit more of a variety and some better long range suited .277 bullets as well.

[amosfella]

There are some available from custom makers as well as Nosler.

[DLab]

The crimp looks segmented,never noticed that type of crimp used on other cartridges.

[DiabeticKripple]

Originally Posted by Nyksta

Unless the ammo cost is similar to 5.56, the longterm price of ammo will be the end of this idea.

I could see this being a pricey round. More than 308 Win for sure.

Originally Posted by rembo

That's a lot of pressure. Steel head cases are not new however.

http://cartridgecollectors.org/cmo/cmo10jun.htm

SIG says it will be the first mass produced case.

Originally Posted by CaberTosser

I'd like to see a cross-section of the two-piece case to see how they are joined. I imagine they've tested extensively to ensure they don't get separated during full-auto fire, that would be a real bugger to have the brass section of it stuck in the chamber during combat, possibly with another round jammed in behind it where the bolt won't close.

They say it’s a 3-piece, with the 3rd piece holding the steel head to the brass case. It would suck to have case-head separation. They are making a million rounds for the military to test to start. They would likely see any failures in that many rounds.