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NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 555271 views.
gatnerd

From: gatnerd

25/11/19

I found this image buried in TFB comments, which in turn lead to a google reverse image search for the original, largest photo:

https://twitter.com/secarmy/status/1055863713058734080

https://i.ibb.co/sKr7Y8R/original-1.jpg

Zooming in:

"Develop suite of ammunition to be fielded with the Next Generation Squad Weapon Program. Ammunition for the first unit equipped 2022 will be will be the General Purpose (GP) round and the Special Purpose (SP) Round."

"Adopt Battle Proven Enhanced Performance Round (EPR) designs for GP Round."

"Implement lessons learned from the XM1158 design for SP Round."

 

  • Edited 25 November 2019 4:13  by  gatnerd
EmericD

From: EmericD

25/11/19

gatnerd said...

Something interesting I noticed in "NGSW Industry Day Slides" is their are two Gov's supplied projectiles - Surrogate and General Purpose.

I always thought that the "surrogate" bullet was the 135 gr SMK bullet that was used during the development of the .277 USA round, but the shape of this SMK bullet does not fit the picture (the ogive looks really secant).

It better looks like a reduced Berger .284" / 168 gr VLD...

gatnerd

From: gatnerd

25/11/19

"I always thought that the "surrogate" bullet was the 135 gr SMK bullet that was used during the development of the .277 USA round, but the shape of this SMK bullet does not fit the picture (the ogive looks really secant).

It better looks like a reduced Berger .284" / 168 gr VLD..."

 Perhaps one of the Berger .270's?

https://bergerbullets.com/product-category/bullets/?caliber=270-caliber

Maybe the 140gr classic hunter?

https://bergerbullets.com/product/270-caliber-140-grain-classic-hunter/

 

Presumably, the 6.8 prototypes we've seen are loaded with the same Surrogate projectile?

6.8 sherwood:

http://soldiersystems.net/blog1/wp-content/uploads/2019/06/image-863.jpg

6.8 sig

https://www.thefirearmblog.com/blog/wp-content/uploads/2019/09/dfdf.png

6.8 TV:

https://www.thefirearmblog.com/blog/wp-content/uploads/2019/09/True-Velocity-6.8mm-Composite-Cased-General-Dynsmics-NGSW-2.jpg

I don't have a trained eye like you for bullets; are they all using the same projectile in their demo cartridges? And does it look like the Berger?

 

From one of the Q&A's, it sounded like the Ogive of the 6.8 GP was longer than that of the 6.8 Surrogate:

71. Question: In reference to Attachment 3 - Ammunition Data’s General Purpose Projectile requirements, does the Government intend to maintain the same envelope for the General Purpose Projectile as the Surrogate? The General Purpose Projectile concept is pushing the maximum envelope of our current system, which was designed around the surrogate. If the maximum overall envelop General Purpose Projectile changes, it will greatly impact overall design parameters; significantly altering development.

 

160. Question: In Attachment 3, can USG modify the GP projectile design to share a common ogive length with the Surrogate and SP Envelope projectiles?

Response: No, the Government does not intend to modify the surrogate projectile since it is designed to mimic the behavior of existing and future combat projectiles.

stancrist

From: stancrist

25/11/19

gatnerd said...

"I always thought that the "surrogate" bullet was the 135 gr SMK bullet that was used during the development of the .277 USA round, but the shape of this SMK bullet does not fit the picture (the ogive looks really secant).

It better looks like a reduced Berger .284" / 168 gr VLD..."

 Perhaps one of the Berger .270's?

Maybe the 140gr classic hunter?

The pic you posted earlier looks like an exact copy of the 130gr Classic Hunter (Part # 27570) shown in the Berger chart below.

Image result for berger .277 vld

stancrist

From: stancrist

25/11/19

gatnerd said...

I found this image buried in TFB comments, which in turn lead to a google reverse image search for the original, largest photo:

https://i.ibb.co/sKr7Y8R/original-1.jpg

Zooming in:

"Develop suite of ammunition to be fielded with the Next Generation Squad Weapon Program. Ammunition for the first unit equipped 2022 will be will be the General Purpose (GP) round and the Special Purpose (SP) Round."

"Adopt Battle Proven Enhanced Performance Round (EPR) designs for GP Round."

"Implement lessons learned from the XM1158 design for SP Round.

Great find!  I wonder if the "GP" and "SP" nomenclature are just for use during development, or will they replace the traditional "Ball" and "AP" terms if the NGSW enters service?

EmericD

From: EmericD

25/11/19

gatnerd said...

Perhaps one of the Berger .270's?

https://bergerbullets.com/product-category/bullets/?caliber=270-caliber

Maybe the 140gr classic hunter?

https://bergerbullets.com/product/270-caliber-140-grain-classic-hunter/

Maybe, but both the 130 grs & 140 grs from Berger are too short (1.24" and 1.274" respectively) compared with the estimated ~1.40" of the EPR bullet. On the other hand, that could explain the comments of some competitors...

gatnerd

From: gatnerd

25/11/19

"The pic you posted earlier looks like an exact copy of the 130gr Classic Hunter (Part # 27570) shown in the Berger chart below."

That does look very similar. 

There's also the question of - how much weight do we give an image in the power point presentation? Is it the surrogate, or just a handy image they grabbed?

A more reliable but more difficult to gauge metric would be examining the shown projectiles used in the 6.8 prototypes.

Right now, my 140gr hunch is based on the 6.8 Cobalt/Mars - it seems odd that they'd be advertising a 140gr @ 3200fps if the Surrogate was a 130gr.

 

"Great find!"  

Thanks! Yeah, I was really tickled when i stumbled across that image in the TFB comments. It was really a stroke of luck / late night internet madness.

 

"I wonder if the "GP" and "SP" nomenclature are just for use during development, or will they replace the traditional "Ball" and "AP" terms if the NGSW enters service?"

Hard to say. I hope they do though.

"Ball" doesn't really do the EPR justice. Its a 2/3 AP projectile that also fragments - which really is a wonderful, 'General Purpose' projectile design. 

And since the EPR - especially this really nasty long 6.8 EPR - has ~comparable penetration to historical AP rounds, I also like 'Special Purpose' as a descriptor for the specialist, extra AP Tungsten projectile. 

 

gatnerd

From: gatnerd

25/11/19

"Maybe, but both the 130 grs & 140 grs from Berger are too short (1.24" and 1.274" respectively) compared with the estimated ~1.40" of the EPR bullet. On the other hand, that could explain the comments of some competitors..."

Yes, the comments definitely suggest the EPR 'GP' is longer then the Surrogate. And of course, if the Surrogate = 6.8 EPR, then there would be no point in the Surrogate for developing the cartridge. 

And if we're talking about a Tungsten 'SP' round, I imagine it would have to be shorter then the 6.8 GP, due to WC being 2x as dense as steel, if the projectile is to remain a comparable weight. 

For example, the Penetrator weight of the M80A1 is 44gr. Same exact size in WC would be 88gr - so a Tungsten M80A1 EPR would weigh 174gr. The result would be a dramatically different velocity from the 130gr original.  

Perhaps maybe a Tungsten core base with polymer tip to lengthen the ogive an mimic the shape of the 6.8 GP? Or replacing the copper base with aluminum? 

 

stancrist

From: stancrist

25/11/19

gatnerd said...

"The pic you posted earlier looks like an exact copy of the 130gr Classic Hunter (Part # 27570) shown in the Berger chart below."

That does look very similar. 

There's also the question of - how much weight do we give an image in the power point presentation? Is it the surrogate, or just a handy image they grabbed?

Good question.  It wouldn't be the first time that a "handy image" was used in one of these presentations.

 

gatnerd said...

A more reliable but more difficult to gauge metric would be examining the shown projectiles used in the 6.8 prototypes.

Left, below:  .270 WSM w/140gr Berger Classic Hunter.  Right, below:  SIG 6.8 NGSW.  Does not look like a Berger bullet to me. 

The ogive looks different, and the tip smaller and more uniform.  Also, it looks like a copper solid, not a jacketed lead-core bullet

Image result for berger .270 cal 140gr classic hunterImage result for ngsw ammo

 

gatnerd said...

Right now, my 140gr hunch is based on the 6.8 Cobalt/Mars - it seems odd that they'd be advertising a 140gr @ 3200fps if the Surrogate was a 130gr.

Well, it also seems odd that the pictured Cobalt/MARS round has what looks very much like a 130gr Barnes TTSX bullet, instead of the BTHP projectile seen in the other 6.8 cartridges.

                                                                            Image result for barnes .277 130gr ttsx bullet

Image result for ngsw ammo

  • Edited 25 November 2019 22:16  by  stancrist
gatnerd

From: gatnerd

26/11/19

"

Good question.  It wouldn't be the first time that a "handy image" was used in one of these presentations.

Left, below:  .270 WSM w/140gr Berger Classic Hunter.  Right, below:  SIG 6.8 NGSW.  Does not look like a Berger bullet to me. 

The ogive looks different, and the tip smaller and more uniform.  Also, it looks like a copper solid, not a jacketed lead-core bullet

Well, it also seems odd that the pictured Cobalt/MARS round has what looks very much like a 130gr Barnes TTSX bullet, instead of the BTHP projectile seen in the other 6.8 cartridges."

Yes, it seems like we have too many speculative data points to really declare the Surrogate any particular projectile or weight with any certainty.

 

So far what we know:

6.8 General Purpose = ~125-135gr Steel Tip EPR with an aggressive, VLD design, ~1.4"/35.5mm long

6.8 Surrogate = Unknown weight projectile. Per design questions, surrogate has a shorter ogive then the GP. And Surrogate is a stand in for a future 'Combat Projectile' that is not the GP, so likely some sort of Tungsten AP load. 

6.8 Special Purpose = Tungsten AP load. Uses "lessons learned" from Tungsten EPR ADVAP XM1158 7.62 projectile, but not guaranteed to be an Tungsten EPR. Per Army comments, projectile may continue to evolve. 

 

As to the 6.8 SP, I'm increasingly less inclined to believe it will be a Tungsten Tip EPR. 

We don't have a model of the 6.8 GP EPR, but we do have Nathaniel's very similar '6.86 Romulan' 125gr EPR:

https://www.thefirearmblog.com/blog/2017/09/09/romulan-vulcan-preference-driven-vs-process-driven-design-field-small-arms-ammunition/

.277 125gr 

jacket + slug = 88.625gr

Slug = 56.675gr

Steel penetrator = 36.375gr

 

s7 tool steel = 7.83g / cm3

Tungsten carbide = 15.63g

-->

WC penetrator = 77.61gr

-->

6.8 Tungsten EPR = 161gr

Since the goal of the 6.8 NGSW is between 2850-3200fps, that would seem to negate the chances for a 161gr 6.8 projectile. 

On the other hand, EPR may be possible with a different base material then copper. Replacing the copper slug with Aluminum would shave off 39.286gr

--> 6.8 Tungsten / Aluminum EPR = 122gr

 

However that then gets back to the problem of the Surrogate. If they were going to use the same 6.8 GP projectile form factor and weight for the Tungsten SP, there would be no need for a surrogate. And since the surrogate is apparently shorter ogive then the 6.8 GP, then it seems the SP will be a different design. 

So we're back to the mystery wagon on what the final SP will be. All we know is that it will be a tungsten something in 6.8. 

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