The NGSW-R is overweight, too powerful for any standard combat scenario seen over the last century, and almost certainly can't even penetrate the armor plates that ostensibly drove its development without using tungsten. Putting it nowhere above what we're already using. And its built on a poor foundation to be a DMR because its still tied to the barrel whip introducing piston mechanism.

The NGSW-AR is firing a hot magnum cartridge, but doesn't have a QC barrel. Despite having a suppressor that makes overheating happen even faster. It had to add a ridiculous bridging top rail because obviously there was little intercompany and intratrial communication as to how large the NGSW-FC optic would be. And beyond that is built exceedingly lightly for the level of power involved in the cartridge its meant to be operating with - almost certainly severely reducing operational lifespan. Leaving us with an M60mk2 in effect. And in the end gives little to no appreciable weight advantage over the notoriously overweight M249 SAW, because the additional ammo weight over 5.56NATO quickly adds up.

These guns are also both chambered in a complex cartridge that can't be used in many existing firearms on account of its very high operating pressure. And even if you could rebarrel for example, an M240 to take the 6.8NGSW cartridge, it'd be at the expense of significantly reduced operational lifespan.

stancrist said:

Perhaps you missed these posts?

Our capability to draw opposite conclusions from the same set of informations will never ceased to puzzle me.

Apsyda said:

The NGSW-AR is firing a hot magnum cartridge, but doesn't have a QC barrel.

The SIG NGSW-AR does have a QC barrel. Not very ergonomic and not designed to be changed when hot during combat, but a QC barrel.

Apsyda said:

It had to add a ridiculous bridging top rail because obviously there was little intercompany and intratrial communication as to how large the NGSW-FC optic would be.

I think that the "bridging top rail" is a direct consequence of the SIG sliding feed tray cover, which is OK only with something like a red-dot sight.

mpopenker said:

the military (any military, Russian included), if unchecked from the outside, tends to create unrealistic requirements Ask any soldier and he wants a gun which is the lightest, the most powerful, has most ammo capacity etc etc SPIW was prime example of that, Russian 'Abakan' in its early iterations was absolutely unrealistic too But in American case any requirement, regardless of how unrealistic it is, is wholeheartedly greeted with the industry because it means 'free' R&D money with very little chances of adoption and subsequent responsibilities for the end project

Which reminds me of the Rabid Bat: a not entirely serious example of procurement (edited version):

In early 2035, the thirty-fourth year of the war against Al Qaeda, the Pentagon issued a White Paper saying that the F22 Raptor, the front-line fighter plane of the United States, was nearing the end of its useful life and needed to be replaced. Not everyone agreed. Various budget-cutting organizations argued that the Raptor had never been used and thus no one could tell whether it had a useful life. Anyway, the job of the Air Force, killing third-world peasants and their families, had been co-opted by drones. America didn´t need a new fighter, said the critics. 

The Air Force countered that the new plane would look feral and make loud, exciting noises. To this, critics could find no rejoinder. Design studies began.

An early question was what to call the new fighter. By tradition, aircraft were named after aggressive but unintelligent birds (F-15 Eagle, F16 Fighting Falcon), unpleasant animals (AH-1 Cobra, F-18 Hornet) ghosts (F-4 Phantom, AC-130 Spectre) or Stone Age nomads (AH-64 Apache). However, something with more pizzazz was needed to get funding through Congress.

Discussion ensued. Suggestions were solicited from The Building, as the Pentagon calls itself. These ran from “F-40 Screaming Kerblam” to the politically marginal “Horrendous Dyke,” whose author believed that it would depress enemy fliers. Going with zoological tradition, the Air Force wanted to call it the Rabid Bat. A congressional wag weary of military price tags suggested “Priscilla,” because no pilot would then go near it and the country would be spared the expense of wars.  (His idea of painting it in floral patterns was not taken seriously.) 

The Air Force prevailed. The Rabid Bat was born.

Squabbling over specifications immediately began. Lockheed-Martin and Boeing Military Aircraft, both expected to bid, wanted a cruising speed of Mach 13, as this was technically impossible and would allow them to do lucrative design work until the entropic death of the solar system. A time-honored principle of governmental contraction is that if you are paid to solve a problem, the last thing you want is to succeed, because you then stop getting paid. This explains the anti-ballistic-missile program, racial policy, and Congress.

Secondary considerations were next addressed, such as speed, range, armament, and stealth. 

Lockheed-Martin said that the price of the program would only be about $987 billion, a steal. Historically-minded critics predicted that after the program was too far along to be abandoned, Lockheed-Martin would discover that the price would be…heh…rather more. This is a standard part of military contracting, with its own accounting category.

A prototype was duly built. Early flight trials began. It was then discovered by the investigative reporter Nickolas Fervently of the New York Times that due to a design error, the guns of the Rabid Bat pointed backward. A redesign, his sources had told him, would cost about $345 billion.

Its that if SIG knew how big the NGSW FC was going to be, they likely would have designed the receiver or feed system differently to account for it. I doubt any SIG engineer is happy with that big bridge rail over top of the action. And should they have known that the NGSW FC was large enough to have its own ZIP Code, they likely would have accounted for  that.

The barrel being easily replaceable doesn't really help much in the field. While our armorer friends in the world can smile about it, everyone using the gun now constantly has to be cognizant of the potentially quite short time to the barrel overheating. At which point there isn't much that can be done about it. Perhaps in the future they'll copy the PKP and put a Lewis radiator system over the barrel. Adding a several lbs to the firearm but giving it more sustained firepower capability.

Apsyda said:

Its that if SIG knew how big the NGSW FC was going to be, they likely would have designed the receiver or feed system differently to account for it. I doubt any SIG engineer is happy with that big bridge rail over top of the action. And should they have known that the NGSW FC was large enough to have its own ZIP Code, they likely would have accounted for that.

I agree that the rail over the feeding cover is far from ideal, but I don't think that it's related to the size of the NGSW FCS, which do not seems to be significantly longer than any commercial 1-8x LPVO.

Apsyda said:

The barrel being easily replaceable doesn't really help much in the field. While our armorer friends in the world can smile about it, everyone using the gun now constantly has to be cognizant of the potentially quite short time to the barrel overheating. At which point there isn't much that can be done about it. Perhaps in the future they'll copy the PKP and put a Lewis radiator system over the barrel. Adding a several lbs to the firearm but giving it more sustained firepower capability.

That's right, but since a rifle like the HK416 could fire 300+ rounds in full auto without overheating, and can fire again the same diet of ammo after 30 minutes of cooling, maybe the lack of "field QC" capability is more a theoretical issue than a real issue?

A 100-rds belt of 6.8x51 mm (with pouch) is ~3.1 kg, so 300 rds is already 9.3 kg of ammo... I don't think that the automatic rifleman will carry more than 4x100 rds (to "duplicate" the 4x200 rds of 5.56 mm currently carried).

EmericD said:

Our capability to draw opposite conclusions from the same set of informations will never ceased to puzzle me.

Well, that is one thing we agree on.  

EmericD said:

       Apsyda said: The NGSW-AR is firing a hot magnum cartridge, but doesn't have a QC barrel.

The SIG NGSW-AR does have a QC barrel. Not very ergonomic and not designed to be changed when hot during combat, but a QC barrel.

Partial disassembly of the gun required + removeable-by-user-only-when-cold barrel =/= quick change barrel

EmericD said:

       Apsyda said: Its that if SIG knew how big the NGSW FC was going to be, they likely would have designed the receiver or feed system differently to account for it. I doubt any SIG engineer is happy with that big bridge rail over top of the action. And should they have known that the NGSW FC was large enough to have its own ZIP Code, they likely would have accounted for that.

I agree that the rail over the feeding cover is far from ideal, but I don't think that it's related to the size of the NGSW FCS, which do not seems to be significantly longer than any commercial 1-8x LPVO.

Judging by the graphic at 9:40 in this video ( https://youtu.be/ZrKOLyLUZmI?t=580 ), the problem is a result of poor planning by SIG engineers. 

With the side-opening top cover, an optic must be mounted either completely on the top cover, or fully on the section of rail behind the top cover.

If the NGSW FCS were to be positioned on the weapon with correct eye relief, it looks like the mount would clamp to both the top cover and the rear rail section, making it impossible to open the top cover.

Apsyda said:

The NGSW-AR...had to add a ridiculous bridging top rail because obviously there was little intercompany and intratrial communication as to how large the NGSW-FC optic would be.

The problem was not caused by a communication failure.  The bridging rail was needed because of a design flaw.

SIG had designed the LMG receiver so that only optics of certain dimensions and/or configurations could be used.

They knew a common FC optic would be used for both NGSW-R and -AR, and yet the SIG LMG was always seen fitted with a compact RDS, while the MCX Spear rifle usually had a much bigger LPVO.  Had the LMG been designed from the start to use the LPVO, the bridging rail likely would not have been needed.

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