[greg_r]

The discussion on the Hornady 6mm ARC in another thread got me thinking about another new cartridge that should be available sometime this year. The Sig .277 Fury. This cartridge is designed to compete for the military's desire for a new belt fed machine gun. It shoots a 6.8 mm (the military seems to be attached at the hip with 6.8mm) 140 grain bullet at 3000 FPS from a 16" barrel. Pressure is over 80,000 psi. It has a brass case with a stainless steel head to contain the pressure.

Sig Sauer has a new rifle for the hunters that want this new cartridge. Called the Cross, it is a precision style bolt action. Retail will be about the same as MSRP of the Ruger Precision Rifle.

The cartridge itself is reloadable, shares the case head size and length as the 308 Winchester.

Sig Sauer says that even if they do not win the military contract, they will still go ahead with the project as they already have the years and money invested in it.

 

[TNTRAILERTRASH]

It may come slowly, really slowly. Sig is shutting down their German manufacturing by September. No telling where their finances will be.

 

[1024Megabytes]

I will only have interest in the .277 Sig Fury round if the military adopts it. This cartridge could possibly become the standard Army soldier's ammo for their rifle. We shall see.

 

[ajole]

Not sure I want to mess with a round that does 80,000 PSI.

 

[greg_r]

Not sure I want to mess with a round that does 80,000 PSI.

This ^^^^^ is where I am at as well.

 

[cicpup]

I will only have interest in the .277 Sig Fury round if the military adopts it. This cartridge could possibly become the standard Army soldier's ammo for their rifle. We shall see.

Already planning your battlefield recoveries?

 

[1024Megabytes]

Not sure I want to mess with a round that does 80,000 PSI.

What is the life of a firearm barrel and firearm that produces 80,000 pounds per square inch? I am thinking not that long. The military may need to let go of the 3,000 feet per second muzzle velocity to get more life out of the firearms.

 

[Shopfox]

I read elsewhere pressures "up to 80,000 psi", so I assume real life will have lower pressures for most loadings.

I'm skeptical of the hybrid case. I think it'll take some time to understand how the cases behave after they've corroded some, and sit for a while in a hot chamber (different thermal expansion properties of the metal).

The chinese communists did some research and came to the conclusion the "ideal" is in the 5.8 to 6.2 mm range. Seeing the progressive trend from 6.8 SPC to 6.5 Grendel to 6mm ARC, the US is/was moving towards that 5.8 to 6.2mm range. To jump back to a 6.8 (.277") bullet PLUS new cartridge technology, seems not to fit the pattern of a successful cartridge.

From Sigs perspective, the development cost is sunk. Bringing it to the market is gravy money.

I don't predict commercial success on this one.

 

[ajole]

The thing is, the US isn’t looking for just a rifle bullet, they want a do it all bullet, for rifles and light machine guns/squad automatics. So....compromises will happen.

But at certain levels, the compromise isn’t too bad. The 6.8 isn’t going to reach .308 levels of kinetic energy in a machine gun, but it might have better terminal ballistics at the right speeds, with the right construction; and it should definitely do the same in regards to 5.56 in either role.

The 6.5 and 6 mm may have better ballistic curves, and might even have really good terminal ballistics in meat targets, but they aren’t going to make a .308 scared.

The real question is, what weight bullet is the military 6.8 using to get that 3000 FPS number we’ve all heard, and what does that do to the equation? If it’s only 100 grains or so, there will be questions about it. That’s great for a rifle when compared to 5.56, assuming load out weight isn’t too bad, and good compared to an M249, but is it enough to let the more general purpose automatics do their jobs, or do we end up with 6.8 + .308 in the system, with a 6.8 that isn’t “that” much better than a 5.56, this requiring the .308 guns to take care of business anyway?

 

[Shopfox]

The real question is, what weight bullet is the military 6.8 using to get that 3000 FPS number we've all heard, and what does that do to the equation?

Not 100% sure, but looks to be in the 135-140gr range.

From tactical-life.com, "This added pressure will drive a 135-grain bullet from SIG's Hybrid Match cartridge 3,000 fps from a 16-inch barrel, and produce 2,694 ft.-lbs. of energy. The 135-grain bullet has a respectable .488 G1 BC.

SIG's 277 Fury Hybrid Hunting load features a 140-grain bullet with a .508 G1 BC, launching from a 16-inch barrel at 2,950 fps. That one produces 2,706 ft.-lbs. of muzzle energy, too."

I just read the case is 3 pieces, not 2. There's a 3rd piece inside the case that locks the brass and steel together. It also uses a proprietary gun powder. Remington 700's and others could theoretically be chambered for this, but they won't be sufficiently durable under the pressures and stresses, so other people making rifles in this caliber are unlikely. Sig's also planning a 6.5 Fury in the future. The case will not fit in an AR-15 platform either. This will be a giant commercial belly-flop.

 

[greg_r]

I was going to say what @Shopfox said. The military loading is supposed to be 135 grains, the hunting load is 140 grains.

 

[CamoDeafie]

I will only have interest in the .277 Sig Fury round if the military adopts it. This cartridge could possibly become the standard Army soldier's ammo for their rifle. We shall see.

You mean like when Remington did the 6.8 Special Purpose Cartridge, only to be told by the Pentagon, "nevermind, we're fine as is"?

 

[1024Megabytes]

You mean like when Remington did the 6.8 Special Purpose Cartridge, only to be told by the Pentagon, "nevermind, we're fine as is"?

5.56 x 45 should have been retired a long time ago. Hopefully they come up with something better for the standard military personnel. As long as it is more effective than 5.56 x 45 out to 400 yards and the rifles last just as long then it is a win for the troops in my opinion.

 

[Shopfox]

You mean like when Remington did the 6.8 Special Purpose Cartridge, only to be told by the Pentagon, "nevermind, we're fine as is"?

The military coming full circle, and selecting the 6.8 SPC would be a fun circus to watch.

 

[TNTRAILERTRASH]

5.56 x 45 should have been retired a long time ago.

Why? Weight is always a consideration.

 

[CamoDeafie]

Why? Weight is always a consideration.

Performance versus the 6.5 and 6.8mm cartridges available now

 

[1024Megabytes]

Why? Weight is always a consideration.

It's round that is less effective than most rifle rounds. They can level up in caliber to an intermediate round (such as a 6.8 millimeter caliber that uses a 110 grain bullet) that is more lethal and gets a longer effective range over 5.56 x 45 and still be able to carry a good deal of ammo.

 

[TNTRAILERTRASH]

Performance versus the 6.5 and 6.8mm cartridges available now

Understand NATO is a big factor too. It is "5.56 NATO."

 

[TNTRAILERTRASH]

It's round that is less effective than most rifle rounds. They can level up in caliber to an intermediate round (such as a 6.8 millimeter caliber that uses a 110 grain bullet) that is more lethal and gets a longer effective range over 5.56 x 45 and still be able to carry a good deal of ammo.

You are double the weight at square 1. 5.56 can take out a hog, and a deer with the right projectile. If the marines had to qualify with irons with 5.56 at 600yds(?) what are we talking about here?

 

[CamoDeafie]

Understand NATO is a big factor too. It is "5.56 NATO."

Only because the US threatened to withhold funding and assets to NATO if NATO didnt adopt 5.56x45 and 7.62x51