Thats a really impressive reduction in recoil. 

Some solid NGSW info:

https://www.thefirearmblog.com/blog/2022/05/16/us-army-shares-details-next-generation-squad-weapons/

The XM5 weighs 8.38 pounds and 9.84 with the suppressor. The XM250 weighs 13 pounds with a bipod and 14.5 with the suppressor.

Currently the XM5 basic combat load is seven, 20-round magazines, which weighs 9.8 pounds. For the XM250 the basic combat load is four 100-round pouches, at 27.1 pounds. For comparison: the M4 carbine combat load, which is seven 30-round magazines, weighs 7.4 pounds, and the M249 light machine gun combat load, which is three 200-round pouches, weighs 20.8 pounds.

The Army has also confirmed that the suppressed XM5 is 36 inches in overall length with a 13.5-inch barrel.

The XM250 has a 41.87-inch overall length (with suppressor) and a 17.5-inch barrel. The weapon’s stock is no longer side folding, reportedly due to Army length requirements, and the weapon is “not considered [to have] a quick-change barrel like the M249.”

Updated specs:

XM5

XM5 w/ Suppressor = 9.84lbs

20rd 6.8 Mag = 1.4lbs 

36" OAL with suppressor, 13.5" barrel 

XM250

XM250 w/ Suppressor = 14.5lbs

100rd pouch of 6.8 = 6.78lbs

41.87" oal with suppressor, 17.5" barrel

6.8 Ammo:

Based on 6.4oz/0.4lb for a 20rd Lancer Mag, and 1.4lb for a loaded 20rd mag, we get 20x6.8 = 1lb.

-->

22.68g per cartridge

+ 1.5 lb optic (probably idk)
+ 0.5 lb peq 15

gee that is one heavy loadout

5.56 fabrl Magnum sounds lovely

I think the optic is closer to 2 - 2.5 pounds.

The gun will definitely be heavy.

Hell even my 16" 5.56 gun with 34mm mount and large tube 1-8 plus bootleg peq15 alike is not light.

Is it workable?

Yeah sure, but when people are already going to slingster style padded slings to spread the load of their 5.56 rifles including me it definitely says that even fully kitted 5.56 m4a1's are probably heavier than is really ideal.

Could this change if guys weren't averaging 100+ pound individual combat load outs?

Probably.

Rifle and ammunition weight doesn't exist in a vacuum and I think that we're about to find this out in a big way.

EmericD said:

       stancrist said: No, you absolutely do not need another weapon. You only need another barrel, one that has the correct rifling twist for the bullet.

The US didn't adopted a "M16A1 with a new barrel", they adopted the M16A2, which is another rifle.

Yes, that is quite true.  However, the M16A2 does not just have a different rifling twist than the M16A1. 

The M16A2 differs from the M16A1 in that numerous changes/improvements  were made to the design.

- New buttstock

- New pistol grip

- New upper receiver w/new rear sight and case deflector

- New lower receiver w/3-rd burst control

- New barrel configuration

- New fore end

- New front sight post

- New flash suppressor

Except for the caliber, the M16A2 was an almost completely different rifle than the M16A1.

EmericD said:

It's plain and simple, the M16A1 can't fire the SS-109 ammo...so you can't consider that "it's just another loading".

You're wrong on both counts.

a.  Like M193, the SS109/M855 is "just another loading" of 5.56x45 ammo.

b.  The M16A1 can fire SS109/M855 ammo (but accuracy is unacceptable).

EmericD said:

       stancrist said: 5.56x45 is still 5.56x45, whether loaded with 55gr bullets or 62gr bullets (or any other weight).

The boxes you show are written ".223 Rem" and not 5.56x45 mm.

Yes, because -- like 5.56x45 -- .223 REM is .223 REM whether loaded with 55gr or 62gr bullets.

But if that minor detail is of such great importance to you, here are cartons labelled 5.56mm:

EmericD said:

       stancrist said: I did not say NATO adopted 5.56 "to please" the US. I said NATO adopted 5.56 because it was a standard US caliber. The only reason there was NATO interest in 5.56x45 was because the US had adopted and was using that cartridge. If 5.56 had never become a US standard caliber, it's extremely improbable that NATO would have wanted to adopt it.

As the US is the main driver behind NATO, and forced the initial adoption of the 7.62 x 51 mm (against the will of a significant number of NATO countries) in 1954, only to adopt the .223 Rem less than 10 years after (and without any considerations to other NATO countries), I think that it's not arguments, but self-fulfilling prophecy.

Call it "self-fulfilling prophecy" if you like, but the fact remains that the only reason 5.56x45 was adopted by NATO is because it was a US standard caliber.

The Belgians would never have developed the SS109 loading if 5.56mm had not been a US standard caliber.

roguetechie said:

Rifle and ammunition weight doesn't exist in a vacuum and I think that we're about to find this out in a big way.

It should prove interesting. 

I see they apparently dropped the original 210-round basic ammo load nonsense. 

That helps a little with soldier carry load, but at the expense of combat endurance.

Yes, combat endurance is something that's a very key interest of mine.

In the case of the machine gunner load 4 100 round nutsacks is probably ok but the rifleman load seems pretty lacking to me personally.

In the case of machine gunners, the ability of 6.8 to turn cover into concealment versus the 5.56 m249 it ostensibly replaces is likely extremely worthwhile.

I personally think pairing 6.8 belt feds and DMR's with 5.56 carbines could be workable but doing both the rifleman and gunner seems like combat persistence will take a dangerous hit.

End of the day the future is in the new optronics , 6.8 makes no sense if you don't drastically up the hit probability with optronics, but then again optronics alone would also drasticaly increase 5.56 and 7.62 effectiveness.

New upgrades to gear over the past 2 decades came with a considerable weight penalty,and the only weight they saved was by cutting the barrel down, even on bullpups its all 16in and shorter barrels. IT seems like today's soldiers even with 5.56 barely carry any more ammo than they did 7.62 in the past.