Sig 6.8 ngsw

[stanc]

http://soldiersystems.net/2019/05/23/sof...ad-weapons

[hill37]

Doesn't this look a lot like the Shell Shock Technologies rifle cases from a while back. SST doesn't mention rifle ammo much on thier sight now. Maybe Sig fixed the head separation problem?

[grayfox]

Hybrid steel case head and brass body for ammo, 3000 ft/sec from 16" barrel with a "recoil mitigation system" (2850 from 13" carbine bbl)... so 2.8 lb recoil vs 13 for the M240, according to the article. Says this "6.8" is kind of like a 270 WSM in performance. Chamber pressure has got to be up there.

[hill37]

The Shell Shock Tech uses an aluminum head with a stainless body. Has to use special reloading dies. Some times head pulls away slightly from body with regular dies. 9mm is all they now I think. 65,000psi rating. https://www.shellshocktechnologies.com/technology/

[LRRPF52]

The Machine Gun weighs in at 11.97 lbs, while the Carbine is 8.1 lbs with no Optic or Suppressor.

So a larger-than AR10, piston-operated carbine, chambered in what amounts to .270 WSM at 8.1lbs empty.

Add on LAM, White Light, LPVO or RDS, and the beast suppressor that will be required to take the beating of insane muzzle exit pressure with a 13" barrel and you have a recipe for a monstrous abortion. Gas port erosion is going to be a witch on that one, unless they use that unobtanium barrel alloy they've been developing.

Bulk volumetric displacement of the ammunition and magazines will be in excess of 7.62 NATO. Good luck with that and the soldier's load.

[stanc]

Bulk volumetric displacement of the ammunition and magazines will be in excess of 7.62 NATO.

I think you're mistaken. The cartridge OAL and case diameter of the 6.8x51 look to be the same as for 7.62 NATO.

[grayfox]

my question is, what's that chamber pressure to get to 3000 ft/sec in 16" barrel I wonder?
Then, what is the exit pressure remaining that enters the suppressor?
Gotta be pretty huge on both counts... 80,000 psi chamber? Idk.

Wait!!! I think I have an excel that does this....
"Calculating Barrel Pressure and Projectile velocity....

Using a .277 caliber rifle, 16" long, 130 gr bullet with exit MV of 3000 ft/sec is a chamber pressure of, wait for it, wait for it....

105,915 psi!!!!!!!

[ATTACH=CONFIG]14288[/ATTACH]

[LRRPF52]

I think you're mistaken. The cartridge OAL and case diameter of the 6.8x51 look to be the same as for 7.62 NATO.

For Sig's submission, that does seem to be the case. They basically are submitting a .270-08.

The others I've seen are .270 WSM.

Either way, both options are a major deviation from being able to carry enough ammo, particularly in a COIN environment where the 1SG hasn't learned what his resupply duties are for all the Platoons and Squads, the CO and XO are retards who never learned their jobs, and you have an element or 2 that start taking hordes of insurgents trying to assert their turf over claimed hoods.

I know several guys in my Battalion and other units that experienced this in OIF, and have also heard experiences 1st-hand from guys that ran black on 7.62 NATO in OEF right before getting exfiltrated just in time.

There were also units in 10th Mountain with the normal mix of 5.56 and 7.62 weapons who almost got overrun by Taliban in OEF. Before the last human wave assault, the PSG was running back and forth to all his hooahs redistributing ammunition.

Cut everyone's basic load by standardizing .270-08 and most of the above situations would have resulted in captured and killed US personnel in the most awful ways.

[stanc]

For Sig's submission, that does seem to be the case. They basically are submitting a .270-08.

The others I've seen are .270 WSM.

Either way, both options are a major deviation from being able to carry enough ammo, particularly in a COIN environment...

I'm not overly concerned about that. If a 6.8 NGSW does get adopted, it should make a good replacement for 7.62 NATO, and sooner or later the leadership will realize it's a poor choice for carbines.

[Sinclair]

I'm not overly concerned about that. If a 6.8 NGSW does get adopted, it should make a good replacement for 7.62 NATO, and sooner or later the leadership will realize it's a poor choice for carbines.

I knew two Marines that served in Vietnam when the Marines were still carrying M-14s. Charlie would send new recruits, old men, women, even children in until they detected a fall off of return fire. Then they would bring up the "A" team and make one final mass assault. Close quarter combat gets intense when they out number you. How many of our guys will die before the brass admits this was all a mistake? As far as the 6.8 what ever goes, if MacCarthur had signed there production of the M-1 for the 7mm cartridge that Garand had developed it for, we would still be using it today. I believe that it was a shortened and blown out .280 Ross much like we morphed the 30-06 into the .308.

[stanc]

I knew two Marines that served in Vietnam when the Marines were still carrying M-14s. Charlie would send new recruits, old men, women, even children in until they detected a fall off of return fire. Then they would bring up the "A" team and make one final mass assault. Close quarter combat gets intense when they out number you.

Yup. My best friend did three combat tours. During one firefight with NVA troops, he used up all the ammo he had for his M14, and resorted to delinking an M60 belt to refill his magazines.

How many of our guys will die before the brass admits this was all a mistake?

We'll just have to wait and see. It may not even get adopted. Look at all the small arms programs that were started during the last several decades, only to end up being cancelled later on.

[LRRPF52]

One of the loudest silences from this whole program is the fact that Hk isn't submitting.

That tells me a lot.

[Sinclair]

Yup. My best friend did three combat tours. During one firefight with NVA troops, he used up all the ammo he had for his M14, and resorted to delinking an M60 belt to refill his magazines.


We'll just have to wait and see. It may not even get adopted. Look at all the small arms programs that were started during the last several decades, only to end up being cancelled later on.


No, we wouldn't.

I meant the cartridge not the rifle. If memory serves me the ballistics was similar to the 7-08.

[LR1955]

Gottcha, I rescend my comment, someone will always think that they have a better mouse trap, just human nature. But I find it ironic that we are now considering adapting a similar cartridge. My concern comes from being haunted by the images of our boys lying dead in heaps with the ramrods stuck down the barrels of their M-16s trying to dislodge stuck cartridges. It reminds me of General Custer's men using their knives to pry out copper casings from their trap door Springfields while the Indians swarmed over them.

Sinclair:

Cite me a single incident of 'our boys lying dead in heaps with ramrods stuck down the barrels of their M-16's trying to dislodge stuck cartridges.'

LR55

[Sinclair]

Sinclair:

Cite me a single incident of 'our boys lying dead in heaps with ramrods stuck down the barrels of their M-16's trying to dislodge stuck cartridges.'

LR55

That, Sir is going to be hard to do since I am certain that all of those pictures have went the way of the Dodo bird. Bad press against the Establishment has a way of disappearing. I was never in Southeast Asia, but I was in the service from 1962 and I did hear first hand accounts of our guys returning back from Vietnam. Stanc and I have exchanged PM's and I will refrain from posting on such subjects as my recollections of some events seem to be at odds with some of you other fellows and I am not a troller. The powers that be have a way of getting what they want inspite of historical evidence to suggest it might be in appropriate.

Sinclair

[LR1955]

That, Sir is going to be hard to do since I am certain that all of those pictures have went the way of the Dodo bird. Bad press against the Establishment has a way of disappearing. I was never in Southeast Asia, but I was in the service from 1962 and I did hear first hand accounts of our guys returning back from Vietnam. Stanc and I have exchanged PM's and I will refrain from posting on such subjects as my recollections of some events seem to be at odds with some of you other fellows and I am not a troller. The powers that be have a way of getting what they want inspite of historical evidence to suggest it might be in appropriate.

Sinclair

Sinclair:

So, no evidence other than 'someone said that they heard from someone who was in Vietnam that.....'.

We all know that DoD failed to use the powder that Stoner insisted was correct for the initial 5.56 ball. And that unless a guy kept the rifle clean, the residue would cause big problems with function. I also believe that cleaning gear didn't appear until after the rifles were issued. Very stupid.

And I am positive that guys paid with their lives because of this entire debacle but they didn't die in 'heaps with cleaning rods stuck down their barrels'. And there was no 'cover up'. Why? Because the problem was heavily reported and was solved.

No, you are not a 'troller'. Have no idea how you even got that notion.

LR55

[stanc]

PCP 6.8 NGSW candidate (center, below). https://www.armietiro.it/ecco-il-68-gp-10459

[BluntForceTrauma]

Forget the "short and fat" cartridge concept, let's just go with Big & Fat.

But what is that beautiful cartridge on the left?

[A5BLASTER]

Forget the "short and fat" cartridge concept, let's just go with Big & Fat.

But what is that beautiful cartridge on the left?

She is kind of sexy ain't she.

[stanc]

Forget the "short and fat" cartridge concept, let's just go with Big & Fat.

LOL. Yeah, I never would've imagined that "obese" might apply to a rifle cartridge. :p

But what is that beautiful cartridge on the left?

Looks kinda like 6.5 Creedmoor to me.