The Army’s new rifle - the XM7

[Astro14]

I can see the inability to use the spent brass for reloading as a hinderance to adoption by the civilian market. Then again perhaps some company will introduce a modified gas system which would allow the use of conventional brass for reloads.

I believe that’s already been done. Sig is selling the .277 Fury (civilian name of the same round) in a conventional brass case, naturally, it is loaded to significantly lower pressures. Much more in line with a 7.62X 51.

Full pressure round:

ELITE BONDED POLYMER TIPPED 277 SIG FURY HYBRID

Elite Bonded Polymer Tipped Ammunition

www.sigsauer.com

Conventional brass case:

ELITE BALL FMJ 277 SIG FURY

Elite Match Grade FMG Ammunition

www.sigsauer.com

Sig has offered the rifle for sale, but it ain’t cheap. I think it was a bit over $3000 just for the rifle, and if you wanted to suppressor, add another grand. I don’t see any for sale in the new caliber right now, but it is this platform, currently available in 7.62x51:

MCX-SPEAR

The civilian version of the U.S. Army's new XM7 rifle.

www.sigsauer.com

Nobody’s talking too much about the details of the optic system, which was contracted out to Vortex. From the pictures, you can see a low, powered variable optic with a red dot on top. It looks like a pretty capable set up, and there are rumor to be some features like automatic ranging, and management of round count, among others.

 

[oil pan 4]

Penetration was a design goal - hence the 80,000 PSI.

The bullet has a velocity at the muzzle of 3,000 FPS, about the same as the M855.

With a weight of 140 grains vs. the M855 weight of 62 grains.

This rifle was designed to penetrate level 4 body armor at 600 yards.

So, I wouldn't worry about body armor penetration.

The real issue is weight, and the plan is to go with 140 rounds of the new stuff vs. 210 rounds of the old. Still adds a couple pounds, but if you are taking out bad guys with one shot, instead of several, then the new round results in more lethality in each soldier.

I have a 6.5creedmoore with a 24 inch barrel that spits out 130s about 3000fps.
It don't take 80,000psi to get there.

 

[Astro14]

I have a 6.5creedmoore with a 24 inch barrel that spits out 130s about 3000fps.

Yeah - but a 24” barrel is a bit unwieldy for a service rifle. This one gets it done with a 16” barrel.

They considered the 6.5 Creedmoor, but out of a 16” it didn’t have enough velocity.

I have a 6.5 CM as well, but it’s an 18” barrel on a .308 AR platform.

 

[oil pan 4]

I can see the inability to use the spent brass for reloading as a hinderance to adoption by the civilian market.

I'll let you know.

 

[Pablo]

6.8SPC guys (me with one in AR) say: Bummer

 

[burbguy82]

Interestingly, the M1 Garand was originally specified in a .276 caliber

I’m fascinated that the army is willing to have two ammunition types these days, when logistics posed such a potential problem in previous major conflicts.

Interestingly, the M1 Garand was originally specified in a .276 caliber.

Interestingly, the M1 Garand was originally specified in a .276 caliber.

I’m fascinated that the army is willing to have two ammunition types these days, when logistics posed such a potential problem in previous major conflicts.

So is NATO going to adopt this round ? There are logistical issues to consider .

As of now, no. You are correct it is a big issue. I suppose they will, unless of course the real target for this ammo is our allies.

This isn't a convincing argument for me

I agree.

isn't fast enough to penetrate lvl IV body armor.

but it is

variable optic with a red dot on top

The thing on the top is an add on, pretty cool actually, it is a laser designator, IR and visible and rangefinder combo, which will give the shooter a holdover depending on distance. Not a red dot.

 

[oil pan 4]

These sig hybrid rifle cases do appear to be reloadable. Not like the shellshock aluminium head stainless body 9mm cases that try to pull apart when sized unless you use the special shellshock industries sizing die.

 

[Astro14]

These sig hybrid rifle cases do appear to be reloadable. Not like the shellshock aluminium head stainless body 9mm cases that try to pull apart when sized unless you use the special shellshock industries sizing die.

Very cool. I sort of wish I had bought an MCX when it was offered in .277 Fury - but then I would have risked getting stuck looking for ammo - and at $4/round right now - that’s not a position in which I want to find myself. Again.

I have a Wilson .338 Federal barrel that I was saving for a build, but I can’t find any .338 Federal ammo, so I have a potential orphan rifle already, don’t need another.

Ironically, I can find all sorts of ammo more easily than that .338 Federal or .277 Fury. Things like .30-40 Krag, or 6.5 Swedish, or 7.5 Swiss. I think I will sit this one out and see how the Army proceeds with the buy, what is made available on the civilian market, and how well they sell.

I had been shopping for a .30 Super carry, and a .327 Federal a while back, look how they worked out…

 

[goingplacesanddoingstuff]

I think it’s a mistake. The cartridge is great for an MG, but overpowered for a rifle. They should have adopted something more like .224 Valkyrie, 6.8 SPC, or 6.5 Grendel.

 

[thastinger]

Penetration was a design goal - hence the 80,000 PSI.

The bullet has a velocity at the muzzle of 3,000 FPS, about the same as the M855.

With a weight of 140 grains vs. the M855 weight of 62 grains.

This rifle was designed to penetrate level 4 body armor at 600 yards.

So, I wouldn't worry about body armor penetration.

The real issue is weight, and the plan is to go with 140 rounds of the new stuff vs. 210 rounds of the old. Still adds a couple pounds, but if you are taking out bad guys with one shot, instead of several, then the new round results in more lethality in each soldier.

I haven't researched the new round but 3000FPS with a 140 bullet can be had with 7.62x51(308 WIN) if you know what you're doing. 2900FPS with 150gr is easy and safe in 7.62x51 with the modern "extreme" powders and the powders are temp stable. 20" barrel though so I guess that would be a drawback.

Seems like we change things for the sake of change sometimes. Wonder if this new case will be reloadable.

 

[oil pan 4]

Very cool. I sort of wish I had bought an MCX when it was offered in .277 Fury - but then I would have risked getting stuck looking for ammo - and at $4/round right now - that’s not a position in which I want to find myself. Again.

I have a Wilson .338 Federal barrel that I was saving for a build, but I can’t find any .338 Federal ammo, so I have a potential orphan rifle already, don’t need another.

Ironically, I can find all sorts of ammo more easily than that .338 Federal or .277 Fury. Things like .30-40 Krag, or 6.5 Swedish, or 7.5 Swiss. I think I will sit this one out and see how the Army proceeds with the buy, what is made available on the civilian market, and how well they sell.

I had been shopping for a .30 Super carry, and a .327 Federal a while back, look how they worked out…

I have zero interest in 6.8 I'll be necking the cases up to 30cal or down to 6.5mm.

 

[oil pan 4]

I haven't researched the new round but 3000FPS with a 140 bullet can be had with 7.62x51(308 WIN) if you know what you're doing. 2900FPS with 150gr is easy and safe in 7.62x51 with the modern "extreme" powders and the powders are temp stable. 20" barrel though so I guess that would be a drawback.

Seems like we change things for the sake of change sometimes. Wonder if this new case will be reloadable.

Yes they are reloadable

 

[burbguy82]

I am not sure what happened on my last post, but what i meant to say was

Interestingly, the M1 Garand was originally specified in a .276 caliber.

This person is correct.

It seems as though they new what they were doing back in the day. I do not think that it was a coincidence. I am sure that no one thinks that there is a magic round that will do all things, in all theaters, because there is not one, but I will concede that the new 6.8x51 is really close. Math is math. To keep the short action, I think the 6.5 Grendel could have been developed to work well in this role, that would not require a full change of gun. I do not think that the current DI system would work well with 85000 psi or more.

In theory, the idea of armor penetration is good, of course, but in practice, the protection of armor is really only effective is the standing or kneeling. It is not effective in the prone. Armor also only covers the vital torso and not the legs, which can be and more times than not, a fatal shot. Armor also really only protects against a fatal shot. A fatal shot does not necessarily mean that a soldier is out of a fight, and in fact, a non fatal shot takes out more than just the soldier. It takes up other manpower and resources. So for the enemy, it is better to wound severely than to kill.

It seems that the weapon, facilitates a change in doctrine, and the two are not really compatible. I may have brought this up before.

 

[ripcord]

I haven't researched the new round but 3000FPS with a 140 bullet can be had with 7.62x51(308 WIN) if you know what you're doing. 2900FPS with 150gr is easy and safe in 7.62x51 with the modern "extreme" powders and the powders are temp stable. 20" barrel though so I guess that would be a drawback.

Seems like we change things for the sake of change sometimes. Wonder if this new case will be reloadable.

Kind of agree. Just to put it into perspective for everyone, the XM7 with the .277 Fury is ballistically equivalent to a .270 Winchester. The high pressure loading gives it the ability to achieve 270 Winchester velocities with a shorter 16" barrel and a smaller case. This is a huge jump in power but it comes with tradeoffs.

The info I could find online about the projectile indicated a copper core bullet with a steel penetrator tip, so it's a normal AP type round and we can't expect any new capabilities in armor piercing. It will in all likelihood take several close hits to penetrate Lvl IV plates.

 

[Astro14]

Kind of agree. Just to put it into perspective for everyone, the XM7 with the .277 Fury is ballistically equivalent to a .270 Winchester. The high pressure loading gives it the ability to achieve 270 Winchester velocities with a shorter 16" barrel and a smaller case. This is a huge jump in power but it comes with tradeoffs.

The info I could find online about the projectile indicated a copper core bullet with a steel penetrator tip, so it's a normal AP type round and we can't expect any new capabilities in armor piercing. It will in all likelihood take several close hits to penetrate Lvl IV plates.

So far, the testing shows that it can penetrate LVL 4 - and they wanted tungsten penetrators, but since China is the principal source of Tungsten in the world, that didn’t make strategic sense.

 

[The_Eric]

Seems like similar ground has been crossed already in the 50's

 

[burbguy82]

.277 Fury is ballistically equivalent to a .270 Winchester.

right, like if there was a 270 win short magnum........

The 6.8 Western is basically a .270 Winchester Short Magnum case with a slightly rebated shoulder (reducing the case's maximum powder capacity) that needs a barrel with a 1:8 twist to stabilize 165 to 175 grain bullets.

6.8 western is the basically the same round, yet another name

 

[ripcord]

right, like if there was a 270 win short magnum........

The 6.8 Western is basically a .270 Winchester Short Magnum case with a slightly rebated shoulder (reducing the case's maximum powder capacity) that needs a barrel with a 1:8 twist to stabilize 165 to 175 grain bullets.

6.8 western is the basically the same round, yet another name

I think I mentioned something about barrel lengths? If you compare 16" XM7 velocities with a 140 grain bullet with the same weight in a 270 Winchester from a normal 22" hunting rifle, you'll see fairly close numbers. I was putting it in terms that the average guy is familiar with.

 

[burbguy82]

I think I mentioned something about barrel lengths? If you compare 16" XM7 velocities with a 140 grain bullet with the same weight in a 270 Winchester from a normal 22" hunting rifle, you'll see fairly close numbers. I was putting it in terms that the average guy is familiar with.

I am not arguing, but agreeing with you.

The real difference I think is the pressure. Further agreeing with the point made on this thread that existing calibers fit this bill. Why not just make a hybrid case for an existing caliber? I think the answer to this might get the thread locked due to politics.


One thing that is important to note on the XM7, is that it is a 13 inch barrel, and the system is made to work with a suppressor. The stated fps is with a suppressor. Another thing about the system that might not be as durable as needed for the mainline forces. In short, it is not a 16 inch barrel.

 

[Astro14]

I am not arguing, but agreeing with you.

The real difference I think is the pressure. Further agreeing with the point made on this thread that existing calibers fit this bill. Why not just make a hybrid case for an existing caliber? I think the answer to this might get the thread locked due to politics.


One thing that is important to note on the XM7, is that it is a 13 inch barrel, and the system is made to work with a suppressor. The stated fps is with a suppressor. Another thing about the system that might not be as durable as needed for the mainline forces. In short, it is not a 16 inch barrel.

Good to know. I thought it was a 16” barrel. 13”? Man, that’s short.

You’re right, to get that velocity from a 13” barrel requires some serious pressure.

One has to wonder if 7.62x51 jacked up to 80,000 PSI would yield the ballistic performance, from the short barrel, that was sought. I think the slightly narrower, lighter bullet gives the ballistic coefficient, and velocity at range, that they’re looking for. The sustainment of velocity at range is what gives this round the penetration ability.

One of the risks of building an extreme pressure round, using an existing caliber/chamber size, is the possibility of someone loading the hot round in a different gun. Sniper rifles, and M14s, both of which use 7.62x51 rounds are not going to handle the extreme round very well.

Never underestimate the ability of soldiers, sailors, or Marines, to use the wrong part, and screw things up if given a chance.

I get the impression that suppression was central to the requirements as well. Every vet I know (including me) has hearing damage. 5.56 unsuppressed, inside structures, is going to cause some hearing damage, unless you’re wearing double hearing protection, and I don’t think soldiers in combat are wearing that kind of protection. Please correct me if I’m wrong, but the door-kickers/action guys I’ve talked with go in without that kind of hearing protection.