I doubt that it's a backpack.  As I recall, the Ironman backpack system developed by the US Army held 500 rounds of 7.62 ammo.

More info from TFB:

How this is 20% lighter remains to be seen...

 The MG-6.8 can be chambered in both SIG’s 6.8x51mm Hybrid and 7.62x51mm, requiring only a barrel change and no change to the bolt. The MG-6.8 takes the MG-338’s technology and compresses it into a package the size of an M249.

It weighs around 12lbs and some weight saving measures have been taken to achieve this with the carrying handle removed and the MG-6.8 does not have the ability to change its feed direction. Additionally, the quick-change barrel feature is not present but is still able to change barrels if needed. 

It uses the same shot-stroke gas piston system and also has a similar recoil mitigation system and internal buffer [to the sig .338] which reportedly brings down its felt recoil to that of an M4 Carbine – 2ft.lbs.

Textrons submission now public:

https://www.thefirearmblog.com/blog/2019/09/12/first-photo-of-textrons-ngsw-prototypes/

LMG looks great.

Carbine looks absolutely awful though, the forward 'tumor' has grown even larger since the 6.5 CT carbine:

This likely would have been better as a bullpup, so that the 'tumor' could be tucked into the stock/above the pistol grip, allowing a slimmer, easier handgaurd.

I imagine this one is tremendously front heavy in terms of balance.

gatnerd said...

How this is 20% lighter remains to be seen...

I'm seeing "brass case" and "metal base", so maybe the base is not steel?.

The weight reduction of ~20% is not an impossible task if the base represent 60% of typical a brass case total weight, and replacing this brass base with lightweight alloy base.

gatnerd said...

Textrons submission now public:  LMG looks great.

Indeed.  And it's interesting to see that, like SIG Sauer, Textron opted to go with a belt-fed machine gun, instead of a mag-fed automatic rifle.

gatnerd said...

Carbine looks absolutely awful though, the forward 'tumor' has grown even larger since the 6.5 CT carbine:

This likely would have been better as a bullpup, so that the 'tumor' could be tucked into the stock/above the pistol grip, allowing a slimmer, easier handgaurd.

I think it would be at least as bad as a bullpup.  It would be extremely ass heavy, and have a length of pull better suited to apes than humans.

Look at the lenght of CT cartridges. Compare them with the pens to the left

They need to give us all here a case or two to play with.

"Look at the lenght of CT cartridges. Compare them with the pens to the left."

Good catch! I didn't even notice them till you mentioned them.

I cropped the image and edited it (poorly) to help make them stand out more:

Also, on the second pass I spotted the 6.8 mag. Looks fairly thick, but is sadly not a quadstack as hinted at in some of Textrons patents.

"I'm seeing "brass case" and "metal base", so maybe the base is not steel?.

The weight reduction of ~20% is not an impossible task if the base represent 60% of typical a brass case total weight, and replacing this brass base with lightweight alloy base."

Several different articles over the last few months have mentioned a steel base / brass body. It's possible they are all wrong in their reporting; that said the bases sure look shiny like machined steel. 

Shell Shock achievers a 50% case weight / ~20% cartridge weight savings using an aluminum base / thin wall steel body, so if they are using aluminum instead of steel that would be good.