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NGSW Reset / Change in Direction   General Military Discussion

Started 16-Nov by Guardsman26; 13310 views.
stancrist

From: stancrist

16-Nov

It sounds like it just might.  sunglasses

gatnerd

From: gatnerd

16-Nov

Guardsman26 said:

Consequently, the US Army is now looking at a compromise requirement with the ability to penetrate level IV body armour to 400-500 metres instead of 600 metres. 

RDECOM/ ARDEC had previously developed EPR projectiles in 6 mm, 6.35 mm and 6.5 mm. It seems that these will be re-evaluated in new case designs. The 6.5 mm EPR-style bullet had already been used by SOCOM for its T&E of 6.5x49 mm Creedmoor. So it is straightforward to establish this as a new NGSW baseline standard, adopting a necked-down version of SIG's hybrid 7.62 case.  Versus SIG's 6.8x51 mm standard, the new round will be lighter and with less recoil.

If true, this would be massively retarded, as 6.5 Creedmoor is basically identical in weight and size to 6.8x51mm, while offering less room for growth to counter future advancements in body armor.

It would make far more sense just to load 6.8 NGSW to 6.5C pressure levels(~60kpsi), while retaining the ability to ramp back up to 80kpsi (6.8NGSW-A1) in the future should it be needed. 

Now if they wanted to actually go with a meaningfully lighter and more compact cartridge (ie like 6mm a non 7.62 parent case) then that would be something else. 

gatnerd

From: gatnerd

16-Nov

Perhaps the time of the 6mm Optimum is now?

Do you recall the case weight of your 6mm Optimum?

TV had a 55% case weight reduction from 7.62 Brass with their .308 polymer case. That could give us a good idea of what a polymer 6mm Optimum would be. 

Gr1ff1th

From: Gr1ff1th

16-Nov

Hmm if only a certain high performance 6mm concept existed, possibly even paired with TV cases for compatibly with existing actions, or in CT format for insane weight savings even with significant performance increases vs 5.56.

For bonus points we could even consider an 80KSPI 6MM Optimum firing 100gr 0.86i7/0.28G7 in a TV case, 7.62 NATO would have a VERY difficult time justifying it's existence in the face of that, let alone against the above mentioned in CT format

  • Edited 17 November 2021 0:04  by  Gr1ff1th
stancrist

From: stancrist

17-Nov

gatnerd said:

Do you recall the case weight of your 6mm Optimum?

I really don't know.  I never weighed it.  It's a .25 Remington case necked down, and the neck shortened to give a 48mm case length.

So, if you happen to know the weight of a .25 Remington (or .30 Remington) case, the 6 Optimum case would be a few grains lighter.

But, the photo was just to show a round of what I think is approximately the desired size, not to be a "plug" for the 6mm Optimum.

I'm not sure if a 0.42" diameter case could deliver the needed MV.  Perhaps it would require something more like the 6mm Unified?

gatnerd

From: gatnerd

17-Nov

stancrist said:

So, if you happen to know the weight of a .25 Remington (or .30 Remington) case, the 6 Optimum case would be a few grains lighter.

Well, we have 6.8 SPC (based on .30 Rem) at ~7.78g per case (depending on brass manufacturer.)

6.8 is 42.3mm OAL, 6mm HAGAR is 45mm OAL, and yours is 48mm OAL, all on the same parent case. 

Lets say +1g to go from 42.3 to 48; seems reasonable and is an easy guess. So 8.78gr per brass case; 3.951g for the TV case based on the 55% reduction.

6mm Hagar 105's are loaded with 29.7gr powder for a target load; for a military (62kpsi) and slightly larger case, lets say 35gr powder. One again just a handy guess here.

6mm Optimum TV guestimate:

6x48 TV Case = 3.951g

100gr Bullet = 6.48g

35gr powder = 2.268g

Small Primer 3.5gr = 0.227g

--> 6mm Optimum TV = 12.93g 

AKA very close to 5.56 brass aka excellent (and also very close to my own goal with 6mm CAKE of replacing 5.56 brass with an equal weight polymer 6mm.)

Gr1ff1th

From: Gr1ff1th

17-Nov

You're not taking into account that you can reduce the powder loading by 15-20% due to the more efficient burn, CT ammo also exhibits this saving, 
 

6mm Revised Optimum TV guestimate:

6x48 TV Case = 3.951g

100gr Bullet = 6.48g

35 -->28 gr powder = 1.8064g

Small Primer 3.5gr = 0.227g

--> 6mm Optimum TV = 12.462g 

When combined with a lighter weight bullet 85gr~ it comes in comfortably under brass cased 5.56, perhaps an approach similar to the Chinese 2 loading system, or even something similar to the existing arrangement of 5.56 DMR's having Mk262 could be explored for further weight and recoil savings, while maintaining commonality


EmericD

From: EmericD

17-Nov

stancrist said:

So, if you happen to know the weight of a .25 Remington (or .30 Remington) case, the 6 Optimum case would be a few grains lighter.

According to data from Nathaniel F, the weight of a .25 Remington cartridge (with a 100 g bullet) is 17.7 g (so, ~11.1 g for a primed case + powder load), and the 6 mm HAGAR is ~15.6 g with a 75 gr bullet (10.7 g for the primed case + powder load), and ~16.6 g with a 90 gr bullet (10.8 g without bullet).

gatnerd

From: gatnerd

17-Nov

Guardsman26 said:

I have received confirmation from an industry source that GD-OTS / Lone Star / True Velocity are now out of the NGSW competition while Textron has voluntarily exited the program.

TV had posted this 14hrs ago on their FB; seems odd to do if they had exited NGSW. 

Guardsman26

From: Guardsman26

17-Nov

It's the GD-OTS gun that appears to have been axed from the program, not TV's ammunition concept. That said, I understand that there are concerns about the accuracy of TV's proposed ammunition configuration. But there is nothing official in the public domain yet. 

The big surprise of NGSW is the performance of the SIG hybrid cartridge case.  Extraordinary strength, lighter weight and potentially lower manufacturing costs all stack-up in its favour. It will be hard to beat. Even so,  Assuming SIG is the winner, TV does not need to say anything before the US Army officially announces the result - although according to the Army's own NGSW timeline, it is now late in declaring a winner. 

We should also remember that companies have an obligation to their shareholders. No vendor will walk away from a potential contract  before an official announcement is made. And even after a winner is chosen, downselected contractors frequently drop the ball after contract award (see UK AFV procurement) so it is in a bidder's interests to maintain a positive attitude.

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