SAAMI Sig Fury .277 Warning

[Muddyboots]

So has anyone looked at this relative to the rifle you are building? Just curious of opinions based upon actual tech facts of running this at 80K in common rifle. No not stirring the pot but real world question based off a technical document. Of course, anyone can do what they want which I believe is their right to choose. I just happen to see it doing some research on a build I was considering.

 

[BRADMOTO]

Who's running this at 80K?

 

[Rodbolt]

That 65,000 psi warning back in 2020 was for the brass cased Fury. The hybrid case is rated to 80,000 psi but in Sig's Arms only as I understand.

 

[Hand Skills]

.277 SIG FURY/6.8x51mm - Everything You Need to Know

Explore The .277 SIG FURY: Learn Its Power & History In March, 2026.

thegunzone.com

It is interesting to compare the print with

270 Redding

A

Thread 'Any experience with a 270 Redding?'

Aug 1, 2022

I am considering a 270 Redding for my next build. Does anyone have any experience with this round?

One of the things I would like to know is the best method for obtaining brass...and which brass would work best? I have been thinking about this build a long long time...and when I first started kicking the idea around I was going to use Remington brass. That doesn't seem to be an option anymore.

The primary purpose for the gun is hunting. I already have a 270 WIN, and wanted something similar with lighter recoil. I have also noticed that components are more plentiful in .277 right now...

• Andy4600
• 270 redding wildcat
• Replies: 15
• Forum: Rifles, Bullets, Barrels & Ballistics

Edited to add;

It seems the trend of ultra high pressure cartridges continues;

120kpsi in a standard M4?!

 

[Lowhighlander]

I built one on an impact for the hybrid case. 17" barrel suppressed. Heavy bolt lift is an understatement. Was worth a try.

 

[Rotten]

As with everything I believe that is put on their for the mitigation of lawsuits.
However I'm wondering if sig is actually achieving 80,000 psi ?
I think this would be like the 1903 Springfield and other older military rifles that the metals used and heat treatments weren't capable of modern pressures.
Maybe sig has a proprietary steel and heat treatment to allow for such high pressures.
I know my company had developed or switched to powdered Inconel that is more heat resistant than the old 716 Inconel that was having cracking issues in the jet engines.
Man that stuff is a nightmare to machine.

 

[lancetkenyon]

Honest question.
What kind of pressures do you think some guys are running with brass cases, that are getting ejector marks, swipes, sticky bolts, and primer pockets that loosen after 2-3 firings with good brass. And claiming 100-150fps over what book max states?

 

[Rotten]

That would depend on cartridge.
However any cartridge that is over pressure will blow primers before you reach the point of blowing the receiver up. My advice is if you want to push a bullet faster than what it was designed for buy a larger caliber. And save your self a trip to the emergency room.

 

[Greatgrandad]

Several of us are running the Fury hybrid cases in standard .277 and various other calibers, and yes, we are running in the 80k range and some higher. The R700 action and a few others are plenty strong.

 

[Little Church Mouse]

As with everything I believe that is put on their for the mitigation of lawsuits.
However I'm wondering if sig is actually achieving 80,000 psi ?
I think this would be like the 1903 Springfield and other older military rifles that the metals used and heat treatments weren't capable of modern pressures.
Maybe sig has a proprietary steel and heat treatment to allow for such high pressures.
I know my company had developed or switched to powdered Inconel that is more heat resistant than the old 716 Inconel that was having cracking issues in the jet engines.
Man that stuff is a nightmare to machine.

"716 Inconel"

We had to deal with that at Newbrook Machine Corp in Silver Creek, NY. Making things for the US Navy, NASA & the Knolls and Bettis atomic power laboratories. I mostly worked with 300 series stainless in the short time I was there 1985-1986.

 

[Rotten]

I might have the number wrong. But yes Inconel is used for furnaces and the need for extreme heat . They also use it for some suppressors.
Its a heavy dense super stanliess steel.
Its in the machinist handbook.

 

[K.E.C. Darkside]

Honest question.
What kind of pressures do you think some guys are running with brass cases, that are getting ejector marks, swipes, sticky bolts, and primer pockets that loosen after 2-3 firings with good brass. And claiming 100-150fps over what book max states?

My guess is 70 to 80 thousand.

Muddyboots that warning on that print is that for the All brass cases or the Hybrid.
I have both of the 277Fury type brass.
I wouldn't recommend high pressure in the All brass case.

Like Lance mentioned, to each his own.

 

[Little Church Mouse]

I might have the number wrong. But yes Inconel is used for furnaces and the need for extreme heat . They also use it for some suppressors.
Its a heavy dense super stanliess steel.
Its in the machinist handbook.

We did test modules and refueling assemblies for submarines, NASA satellite fuel cells, etc.

 

[MagnumManiac]

This is an interesting question.
Proof loads often exceed 80,000psi, proof is 20% higher than normal max, which normally shows nothing more than a stiff bolt opening.
The cases are tossed afterwards.
I saw the proof loads and the testing at CZ in the 90's, no special equipment or procedures were used other than a blast shield surrounding the action.
I queried what sort of pressures a CZ 550 Safari Magnum could handle, and they said the action is tested at 200,000psi in destruction testing.
It often did not rupture at that pressure, taking it to 250,000psi to cause a rupture.

So, as the adage goes, it is the case, solely the case, that is the weak link.

Cheers.