The XM8 was just another 5.56 that didn't do anything an M4 did.

The Army has spent tens of millions of the last 4 years developing bullets for this new rifle.

Although it is being sold as an M4 replacement, It will most likely end up as a 7.62 replacement, and 5.56 replacement in the M249, with maybe a few M5s per squad.

I think both these guns are here to stay, but maybe not in the quantities some are pushing.

In the end I wouldn’t be surprised if they buy it for a DMR (still stupid) and for platoon machineguns. But that’s about as far as it ought to go and then some.

At least XM8 was a net neutral proposition. This nonsense is actually going to be a step backward.

Did the XM8 ever get this far as far as actual contracts awarded?

Unknown. One smart thing they did is use an etched reticle, so when the battery dies it still works as a 1-8x LPVO.

The rifle also has a 'power rail' that is electrically and digitally conductive, and work has been done on a clip on lithium battery pack to provide additional power.

https://tworx.com/intelligentrail/

In terms of battery consumption, a previous 'smart scope' was the Steiner ICS, which may show how the NGSW-FC would be employed. For the ICS, the laser range finder and computer is only activated when the shooter presses a tapeswitch to laze the target. Otherwise its just using the power to electrify the red dot.

In addition to the weight, the Suppressor is a potent recoil reducer. Tests of .308 suppressors show a ~ 33% recoil reduction, similar to a compensator.

Doubt.

Agreed.

Just wasting more money for either hypothetical or barely measurable improvement.

There is an improvement and it is measurable. The problem is that they are forgetting about what declines or suffers at the hand of that improvement. Also, whether or not there's really a need in the first place.

The most ballistically interesting part of this will be the M240 conversion to 6.8x51mm

Currently SIG has said:

6.8x51 135gr
13" = 2850fps
16" = 3000fps

The M240B uses a 22" barrel; I wouldnt be surprised if we see 135gr @ 3200fps from the M240B.

Why wouldn't they just replace the 240 with the new MG.

Very interesting.  

That puts it at about 10 ft lbs which is the recoil of a .243 Win, .257 Roberts or .30-30 Winchester.

For reference, a 5.56 goes ~3.9 ft lbs.  

Cost and it probably doesn’t last as long because stampings.

-M240 set up in vehicles and integrated with fire control systems / co-axe guns
-M240 has tripod setup for long range use by dedicated Machine Gun Teams
-M240 almost certainly has a higher sustained rate of fire before overheating
-US has 100k M240's in service per earlier article

Yep.

I'd imagine they could do all of that with the new one. And everything gets replaced eventually.

If its an easy conversion, I guess why wouldn't you want to integrate it into the legacy guns? The 240 is an excellent gun, just heavy. The SIG will most likely displace it in the dismounted role, but as a coax or mounted gun, who cares about the weight.

True.

I doubt it, besides the reasons mentioned above, the XM250 although belt fed is meant for the AR role.  I doubt it will have anywhere near the durability of the M240, especially when mounted.  Similar to how the Mk48 destroys itself when mounted.

Good point. I forgot about that. I remember being excited about the MK48 when we got them and then disappointed with them.

This, I bought case of it in .308, it works and weighs a lot less in a load out. 6 25 round mags basically same weight as 8 5.56.

Accurate, no problems. Should use the TV ammo in the spear if they had to have the McX. What about the abysmal accuracy of the sig LMG? 8 MOA?

That’s atrocious. Talk about a huge beaten zone at 1k. Only like 10’ dispersion no big deal.

I don’t trust sig after Cohen took over, too many lackluster guns I felt suckered after buying.

The TV cant meet the specifications in the short spear barrel. Thats why it was put into a bullpup. Has the rumor of the accuracy of the LMG actually be substantiated?

And just to put potential longevity into perspective, the MK48 is a 18lb LMG firing a 60kpsi cartridge, and the SIG LMG is a 12lb gun firing 80kpsi ammo.

I'm sure they've figured out how to make the gun last a good amount of time, but I'd be shocked if it could really hold up for the 250k+ rounds M240s are reportedly able to.

The M-4 and M-16 family of rifles will still be issued in 2040.

More than likely you will see an AR platform built around the new ammunition, and the military will end up fielding that.

Does it pass the drop test?

Attached File

The Army specs of drop testing, or the actual real world test of dropping it and seeing if loud noises ensue?

We will end up with a version of the M4 chambered in the .277.

I'm curious about what changes might be needed for 80k psi.

A look at the leaked 6.8 GP projectile, vs M80A1 and M855A1:



Projectile is rumored to be 130-135gr. A source I trust estimates the G7 BC at ~ 0.285 based on the length/diameter/shape of the 6.8 projectile vs the 7.62 M80A1.

6.8 GPC 130gr G7 .285 @ 3,000fps from 6.8LMG=

600m = 1984fps / 1136 ft/lbs energy

800m = 1700fps EPR fragmentation range* (assumed based on M80A1 fragmenting at 1700fps in youtube tests)

1255m = 1125fps Supersonic range / 365ft/lbs energy

Overkill for a rifle round, but should be hell on wheels for a LMG / GPMG round.

Major advances in prosthetic limb and face technology.

Beefier bolt lugs and barrel extension.

Probably lengthen the gas system and adjust gas port size.  

Buffer weights and spring weight would probably need to be tuned.




I'm most curious about Sig's claims about barrel life.  What did the firing schedule look like?  What surface treatments or alloys are they using to get that barrel life?  Stellite liners?   What does the accuracy look like on a new, partly worn, and mostly worn barrel?

When discussing this caliber with someone a few weeks ago, I had the same thought about Stellite liners. Considering they're already in use for some applications, it seems like the most reasonable way to combat throat erosion.

I also think we just need to accept a higher rate of erosion across the fleet and budget for it.

It would be a hell of a lot easier, cheaper, and logical to accept a lower effective range and projectile energy (which is still significantly higher that what is actually useful on the battlefield) and leave shit alone.

Work on caseless, caseless/telescoping, liquid propellant, or even e-mag or directed energy weapons, and keep 5.56 until your next-Gen shit is ready.

The amount spent on machine gun barrels is so minuscule that it is better to go for the performance.

Caseless and Case Telescoped are never going to happen, they are a good idea fairy project with way too many downsides.

The Army funneled millions of dollars over the last 20 years to AAI/Textron for the LSAT program, then even gave them this Next Gen 6.8 program as a sole source contract to develop a high performance 6.8 CT gun/round.   Only after they failed to meet requirements did this competitive program come about, which was down selected to 3 competitors, one of which had the clear leg up since the Army had just spent a few years and millions of dollars helping them develop their gun and ammo.   Yet Cased Telescope failed once again.

It's a dead end technology sold by snake oil salesmen.

Agreed.


Caseless presents way more problems in implementation than it solves.

Case telescoped looks like a shit show if you want any kind of accuracy.




An optimal 6mm cartridge is a good idea.  80k PSI may not be.  We will see.

Well, not if your definition of "optimal" is "something I can carry less of and not make hits with as quickly until ranges get out past 600m".

Maybe something like 6mm ARC with a rifle built around it, similar to the LWRC Six8, would be useful. Compared to a 5.56, it’d still trade some close range effectiveness for long range effectiveness due to somewhat greater recoil. It’s a relatively small side-grade and almost certainly not worth large scale military adoption.

A little bit more useful?  Maybe.

Enough to field a replacement for M249 around?  Doubtful, but possible, mainly because M249 is a passable design that actually has some room for improvement (namely constant recoil systems).

Enough to build an M4 replacement around?  Not even close.

Did somebody post this?

Well here it is anyway.

https://www.gunsamerica.com/digest/277-sig-fury-demystified/

The 6mm ARC is just a barrel swap (maybe a barrel and a bolt).  I was about ready to order a barrel from Criterion but brass and ammo is unobtanium right now.

A concept I came up with a few years ago as a 'optimal 6mm / squad round' was '6mm CAKE' as in 'have your cake and eat it too.'

6mm 85gr 0.45 G1 @ 3000fps, using a polymer case to keep cartridge weight equivalent to 5.56 brass. Cartridge would basically be a 6mm HAGAR @ 62kpsi, so it could use 30rd mags equivalent in length to the 30rd 6.8 SPC mag for LWRC (although COL would be about 2.4-2.5").

That would give a round with the weight and ammo load of 5.56, with the recoil of 7.62x39, and the supersonic/fragmentation range better than 7.62x51 M80A1.

...

A similar cartridge could likely be created using SIG's high pressure case design. Using 5.56 as the parent case, necked up to 6mm, and run at 80kpsi. This would only be ~1g more per cartridge then 5.56, while having identical magazine heights (though still longer COL of 2.4-2.5")

...

High pressure cases and polymer cases offer a tremendous amount of potential - they are super cool technologies. Its just going with 6.8x51 battle rifles with 13" barrels thats retarded.

But if properly applied to a more efficient cartridge like 6mm CAKE... really cool stuff can happen.

I know it's an IDIQ contract, and we might end up buying like 500 of them, but holy fuck have we just decided that everything should cost HK and Knights money or worse?

The ratio of XM5 to XM250 and cost for each annoyingly aren't broken out anywhere that I've seen, and the contract includes support (which I take to mean warranty parts replacement and ongoing development) but still, this is a tid bit crazy:

• Up to $4,500,000,000


• Up to 250,000 weapons


• $18,000 per weapon

I remember seeing a pricetag on an M110 at somewhere in the 10k range and being baffled at that figure, but at least we weren't buying them in the tens or hundreds of thousands.  I'm more pissed off than baffled at this. What happened to economy of scale?

And lest ye forget the accompanying NGSW-FC contract for the XM157 optic, which is NOT a part of that $18,000 per unit cost:

• Up to $2,700,000,000


• Up to 250,000 optics


• $10,800 per optic

I can see a weapon system with a $28,800 price tag having a place in limited use with SOCOM.  But are we really thinking about giving one of these setups to every unwashed private in the Army?

This is so far beyond any precedent that I don't even know what to say.  The latest per-unit cost (that I can find) of an M4 was $673, the M27 IAR $1,300, the M249 $4,087, and the M240 $6,600.

And don't even get me started on the absolute clusterfuck that an 80,000psi round will be in an organization that really has no concept of preventative maintenance.  Like they're going to start logging round counts so they know when to replace the barrel and bolt before those parts ask for replacement in their own catastrophic way...

The contract includes ammo, parts, and maintenance.

The Estonians are already doing just that with their new LMT rifles.

The technology exists, so I wouldn't be surprised if it's used with the XM5 at some point for precisely the reasons you mentioned in terms of wear and tear.

I will dispute the relevance of that part.  Allow me to elaborate.

Yes, the NGSW solicitation was for a weapon system including ammo and an optic - but the optic as we have seen has already been given a separate contract.  And to my interpretation, it seems like the purpose of the NGSW contract was to develop the ammunition and provide initial capacity, not necessarily award a sole-source supplier indefinitely.

Lake City is gearing up to produce 6.8 and it's been put out that the government is already supplying projectiles to Sig for their own efforts in this initial phase.

This is the best info I can find on the subject of ammo going forward, from the Army's press conference transcript, emphasis mine:



I want to just emphasize this part again:



That tells me Lake City is going to be pumping out M1184/M1186 fully in-house.

Even if Lake City will be complimentary to Sig Sauer's own production, there's still this:



As anyone who reloads can tell you, bullets are a not-insignificant portion of the expense, and the EPR projectiles are probably among the most expensive to make.

But let me steel man the argument that a huge chunk of the 4.5 billion is for ammo.

We'll have to make some assumptions.  First, that the NGSW cost about 50% more than their peers. I'll put the M5's peer as the IAR which costs the Corps $1300 per sample, and the M250's peer as the M249 (which it's intended to replace), which costs about $4087. So let's say the actual per-unit cost of the M5 is $1950 per, and the actual cost of the M250 is $6131 per.

Now we've got to break down that 250,000 units somehow.  Per the press conference, the intended amount of M5's to outfit the "close combat force" is 107,000 and the number of M250's is 13,000. So we're looking at a 89%-11% split, roughly. 89% of 250,000 is 222,500 and 11% is 27,500.

222,500 M5's at $1950 is $433,875,000 and 27,500 M250's at $6131 is $168,602,500. So that's $602,477,500 of the contract accounted for.

Let's be EXTRA GENEROUS and assume that the cost of spare parts amounts to 100% of the cost of the weapons.

That gets us to $1,204,955,000. We're still 3.3 billion dollars short.  Is all of that 3.3 billion dollars ammo?

Sig is selling the ammo to the civilian market currently at $80 per 20 rounds.  $4 per round is obviously not what the government will end up paying.  I would put that figure at closer to 50 cents a round (when you're talking millions of rounds) but let's be extra generous and say it's $1 per round, government cost.  Keep in mind, Sig is using 100% government supplied projectiles.  So the Army is paying Sig to load Army projectiles in Sig cases, this $1 doesn't even cover the full cost per round. That's easy math, 3.3 billion rounds of ammunition.

Now we have to figure in Lake City's production.  Let's conservatively say (and this is hysterical to me) that Lake City is only matching what Sig puts out.  Not doing something more realistic like 90/10 or 80/20. So we're at 6.6 billion rounds of ammunition.

Now factor in that this contract is for ten years, and those weapons will be delivered over the course of ten years. Let's say that Sig will deliver 25,000 weapons per year. So the cumulative fielded number of weapons in year one will be 25,000, year two will be 50,000, year three will be 60,000, etc. To make this math easy, we'll think of things in terms of weapon-years so we can break the ammo down per weapon, per year fielded.

25,000 + 50,000 + 75,000 + 100,000 + 125,000 + 150,000 + 175,000 + 200,000 + 225,000 + 250,000 = 1,375,000 "weapon-years".

6.6 billion rounds to cover 1,375,000 "weapon-years" means that each weapon will be firing 4800 rounds per year. When I was in, I felt lucky to fire a fifth of that per year.  Often, it was less.  And 4,800 rounds per year sounds like you're going to be going through two barrels a year with this new extreme high pressure ammunition.  That just doesn't square.  I see no way on earth those rifles from the initial batch will be able to fire 48,000 rounds over ten years. I don't think Sig will be putting out billions of rounds at all. I think that will fall to Lake City and will be outside the scope of the $4.5 billion contract.

This doesn't provide any hard numbers, but I'll add this from the press conference I linked earlier, which should be illuminating:



It's obvious that the Army's intent is to produce the vast majority of all 6.8x51 ammunition, they just need time to build the infrastructure at Lake City first.  I wonder if Winchester-Olin will run that, too?

Last, I'd like to point out this quote from Mathew Moss at Overt Defense:



That's a measly 4.5% of the 3.3 billion figure I used to steel man your argument, and seems like a much more likely number.

The only reasonable conclusion I can draw here is that this rifle is pants-on-head stupid expensive. I can't wait to see this covered in Rand Paul's Festivus fraud-waste-abuse report this year.

I can't confirm or deny your numbers tho as a WAG I think you make a lot of sense.

I still see trouble ahead on the ammunition;  pressures & mass production of hybrid cases, barrel life, parts breakage to start with.

The only absolute upside I see to this program for the taxpayer is if he is sort of Fuddy like me and can eventually score some cheap bulk .277 diameter bullets for his .270 Winchester.