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NGSW Phase 2 Consolidation and info   Small Arms <20mm

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

From: EmericD

24/11/19

renatohm said...

Something like PAW 20 or GM-94 is a much better solution than a 6.8 behemoth.

But that "6.8 behemoth" could be a good replacement for the 7.62 mm NATO, and maybe a not so bad replacement for the 5.56 mm...

With a suppressor, the recoil of a 135 gr bullet @900 m/s will be similar to that of the 7.62x39 mm (~8 N.s), the weight of the round could be between 17 g and 22 g so all-in-all similar to a 7.62x39 mm with it's heavy steel mag.

The difference will be the hit probability and terminal effect. Staying inside .270 Winchester ballistics (135 grs @900 m/s) and a L/D ~5 of the 6.8 mm EPR bullet with a moderately secant ogive (i7 equal or better than 0.90), the bullet will be supersonic up to 1200 m (400 m more than the 7.62 mm NATO) and the 600 m impact velocity should be around 590 m/s (vs. 450 m/s for the 7.62 mm NATO).

Gelatin test made with the M80A1 bullet have shown complete fragmentation of the round at impact velocity around 1900 fps, so that's a fragmentation range of more than 600 m compared with 430 m for the M80A1.

https://www.thefirearmblog.com/blog/2016/07/12/extreme-fragmentation-range-from-m80a1-epr-300-blackout-test-from-the-wound-channel/

I easily imagine that a round that could fragment "instantly" between 0 and >600 m, delivering more than 1500 J to the target and still being able to penetrate more than 14" could be seen as a game changer from a US military point of view.

Using a steel arrow that's ~60% of the bullet length (https://www.thefirearmblog.com/blog/2016/07/23/taking-a-look-inside-the-armys-devastating-new-m80a1-7-62mm-round/), and a bullet length of >35 mm, the steel arrow should be around 21 mm long, so at an impact velocity of 640 m/s (500 m range) the armour penetration should be around 7 mm of RHA. That's similar to the performance of the best tungsten carbide core 7.62 mm NATO round at this range, but using a steel core.

Remember, when the US Army choose the M855A1 to replace the M855, the "advertising" was that the EPR bullet was "green" and avoided 2,000 metric tons of lead annually, when the "real argument" was that the terminal ballistics of the new bullet were simply much better than the M855.

For the 6.8 mm, the advertising is that the Army need a better AP round to defeat body armour at extended range, but that's only a small part of the truth. I think the army is seeing the possibility to achieve better terminal ballistics than the 7.62x51 mm for the recoil and weight of the 7.62x39 mm, so that's probably a good deal.

stancrist

From: stancrist

24/11/19

EmericD said...

Remember, when the US Army choose the M855A1 to replace the M855, the "advertising" was that the EPR bullet was "green" and avoided 2,000 metric tons of lead annually, when the "real argument" was that the terminal ballistics of the new bullet were simply much better than the M855.

There was no such distinction between "advertising" and "real argument" when M855A1 was adopted.  Actually, the "advertising" done by the US Army touted the improved terminal performance of M855A1.  Here is a 2010 article posted on the US Army web site:

https://www.army.mil/article/48657/evolution_of_the_m855a1_enhanced_performance_round#:~:targetText=PICATINNY%20ARSENAL%2C%20N.J.%20%2D%2D%20Perhaps,than%20their%20weapons%20and%20ammunition.&targetText=The%20Army%20adopted%20the%205.56,the%20first%205.56mm%20round.

 

EmericD said...

For the 6.8 mm, the advertising is that the Army need a better AP round to defeat body armour at extended range, but that's only a small part of the truth. I think the army is seeing the possibility to achieve better terminal ballistics than the 7.62x51 mm for the recoil and weight of the 7.62x39 mm, so that's probably a good deal.

I think you have it backwards.  As the name indicates, 6.8 NGSW is to replace 5.56 NATO squad weapons.  The improved armor defeat vs 5.56 is the primary purpose.

Increased terminal effects on soft targets vs 7.62 is a secondary result, but I question the idea that it was an "unadvertised" goal, as you appear to be suggesting.

 

EmericD said...

Gelatin test made with the M80A1 bullet have shown complete fragmentation of the round at impact velocity around 1900 fps, so that's a fragmentation range of more than 600 m compared with 430 m for the M80A1.

I easily imagine that a round that could fragment "instantly" between 0 and >600 m, delivering more than 1500 J to the target and still being able to penetrate more than 14" could be seen as a game changer from a US military point of view.

I do not see how extending the fragmentation range is likely to change the game noticeably, if at all. 

However, I can see a significant adverse effect on the game, as a consequence of the greatly reduced ammo capacity of 6.8 vs 5.56 weapons.

The physical size of 20-rd 6.8 magazines would seem to mandate a return to basic ammo loads of only 100 rounds, which would have a serious negatve impact on combat endurance.

Image result for german soldier with g3 rifle

  • Edited 24 November 2019 15:22  by  stancrist
Farmplinker

From: Farmplinker

24/11/19

.270 WSM ballistics with 7.62x39 recoil is an intriguing idea. As Patrick Sweeney has pointed out, most people can shoot fast and accurately only with 5.56x45 or less recoil. And even with good optics, most shots fired will be for suppression. So the reduction in ammo supply will probably not be worth it.

EmericD

From: EmericD

24/11/19

stancrist said...

EmericD said...

Remember, when the US Army choose the M855A1 to replace the M855, the "advertising" was that the EPR bullet was "green" and avoided 2,000 metric tons of lead annually, when the "real argument" was that the terminal ballistics of the new bullet were simply much better than the M855.

There was no such distinction between "advertising" and "real argument" when M855A1 was adopted.  Actually, the "advertising" done by the US Army touted the improved terminal performance of M855A1.  Here is a 2010 article posted on the US Army web site:

https://www.army.mil/article/48657/evolution_of_the_m855a1_enhanced_performance_round#:~:targetText=PICATINNY%20ARSENAL%2C%20N.J.%20%2D%2D%20Perhaps,than%20their%20weapons%20and%20ammunition.&targetText=The%20Army%20adopted%20the%205.56,the%20first%205.56mm%20round.

You're right. I've seen so many articles advertising the M855A1 as a "green round" that I missed the original claims.

stancrist said...

I think you have it backwards.  As the name indicates, 6.8 NGSW is to replace 5.56 NATO squad weapons.  The improved armor defeat vs 5.56 is the primary purpose.

Yes, but if you just want to improve armor defeat you can just re-issue 7.62 mm NATO weapons, that's a fact known since the '80s (as stated in the above link).

With this 135 gr / 6.8 mm bullet, it seems that they start from the same point that the T65 round with the T104 bullet, but with a better shaped bullet (fragmenting + VLD), and the "light rifles" are all equipped with a more effective muzzle brake (suppressor).

stancrist said...

However, I can see a significant adverse effect on the game, as a consequence of the greatly reduced ammo capacity of 6.8 vs 5.56 weapons.

The physical size of 20-rd 6.8 magazines would seem to mandate a return to basic ammo loads of only 100 rounds, which would hav a serious negatve impact on combat endurance.

The US army seems to want to retain a 210 rds combat load. I don't know if that's possible.

Basically, instead of 180 rounds on the soldier (3 double pouches, 6 magazines), we should see this number dropping down to 120 rounds or maybe 160 round (4 double pouches as shown in the picture?).

From my perspective, the combat endurance did not seemed to have increased significantly when the MAS 49/56 was replaced by the FAMAS...

EmericD

From: EmericD

24/11/19

Farmplinker said...

.270 WSM ballistics with 7.62x39 recoil is an intriguing idea.

I stayed with conservative values, a 135 gr bullet at 900 m/s is within standard .270 Winchester realm, not "short magnum" ballistics (if you don't want to achieve this from a 13" barrel).

Farmplinker said...

As Patrick Sweeney has pointed out, most people can shoot fast and accurately only with 5.56x45 or less recoil. And even with good optics, most shots fired will be for suppression. So the reduction in ammo supply will probably not be worth it.

That's right when there is only one shooter, engaging clearly defined targets.

In the field, with several soldiers trying to maneuver without shooting at each other, and firing at undefined or concealed targets, the difference seems less impressive.

At least, during the SAWS study (which was strongly biased towards the 5.56 mm), the "light and fast pointing" 5.56 mm were not found superior to the "heavy and slow firing" 7.62 mm during short-range & ambush scenarii...

gatnerd

From: gatnerd

24/11/19

"Gelatin test made with the M80A1 bullet have shown complete fragmentation of the round at impact velocity around 1900 fps, so that's a fragmentation range of more than 600 m compared with 430 m for the M80A1.

https://www.thefirearmblog.com/blog/2016/07/12/extreme-fragmentation-range-from-m80a1-epr-300-blackout-test-from-the-wound-channel/"

In an updated test, M80A1 is still fragmenting instantly at 1745fps. 

https://www.youtube.com/watch?v=aH_gijsxr9E

1700fps is in line with other commercial JSP/JHP/Ballistic tip rounds, so for comparisons I use 1700fps as the frag range (although it could be even lower.)

 

"Using a steel arrow that's ~60% of the bullet length (https://www.thefirearmblog.com/blog/2016/07/23/taking-a-look-inside-the-armys-devastating-new-m80a1-7-62mm-round/), and a bullet length of >35 mm, the steel arrow should be around 21 mm long, so at an impact velocity of 640 m/s (500 m range) the armour penetration should be around 7 mm of RHA. That's similar to the performance of the best tungsten carbide core 7.62 mm NATO round at this range, but using a steel core."

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

General Purpose is the 6.8 EPR I linked earlier.

But the Surrogate appears to be a lead core VLD. This is further supported by the Cobalt/MARS entry - which used a 140gr lead VLD. 

If the Surrogate is the stand in for the Tungsten AP round, and the Surrogate is 140gr, I'm curious if that means that the 6.8 GP is a different (presumably lighter) weight, say 120-125gr? 

It also raises a question about whether the 'ADVAP' is actually a tungsten tip EPR. S7 tool steel is 7.83g/cm3, whereas WC is 15.83g/cm3, so the two projectiles would end up radically different in weight.

For example, if the 6.8 GP is 125gr with a 50gr penetrator, 6.8 ADVAP would have a 101gr tungsten tip of the same volume due to the density, increasing overall projectile weight to 176gr. 

Since the Surrogate round is 140gr, its reasonable to assume the AP round is ~140gr. Which suggests that either the GP round is lighter, or that the AP round has a different construction to the EPR (either not EPR, or using a much lighter base material then copper.)

 

 

 

stancrist

From: stancrist

24/11/19

gatnerd said...

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

General Purpose is the 6.8 EPR I linked earlier.

But the Surrogate appears to be a lead core VLD.

If the Surrogate is the stand in for the Tungsten AP round, and the Surrogate is 140gr, I'm curious if that means that the 6.8 GP is a different (presumably lighter) weight, say 120-125gr? 

It also raises a question about whether the 'ADVAP' is actually a tungsten tip EPR. S7 tool steel is 7.83g/cm3, whereas WC is 15.83g/cm3, so the two projectiles would end up radically different in weight.

Since the Surrogate round is 140gr, its reasonable to assume the AP round is ~140gr.

From all I've seen on the subject, I figured the Surrogate bullet is a substitute for the GP projectile, with "GP" being the current name for what originally was called ADVAP.

Is there reason to think GP and ADVAP are two different bullets?  Has anyone seen the "ADVAP" term being used by the Army or industry since the GP bullet was debuted?

gatnerd

From: gatnerd

24/11/19

"From all I've seen on the subject, I figured the Surrogate bullet is a substitute for the GP projectile, with "GP" being the current name for what originally was called ADVAP."

From the looks of it, contractors and Gov't testing involves testing both the GP and Surrogate, with plenty of GP's provided. So the Surrogate doesn't make sense as a Surrogate for GP, given that they were handing out large quantities of the GP.

https://imlive.s3.amazonaws.com/Federal%20Government/ID5041233544762060809463086928281536454/NGSW_Industry_Day_Slides.pdf

 

Some more info:

"Additionally, offerors must develop two different ammunition cartridges utilizing government specified 6.8mm projectiles.

* General Purpose (GP) per Drawing titled “6.8MM GENERAL PURPOSE (GP)”. The GP cartridge provides all-purpose solutions for combat, limited training, and basic qualification.
* Surrogate per Drawing 13072652. The surrogate cartridge is designed to mimic the behavior of combat projectiles from a weapon design standpoint. Surrogate projectiles may not be completely representative of the final combat ammunition configuration which are expected to vary during development. Surrogates are intended to be a close replacement shape of the final combat rounds."

http://soldiersystems.net/2018/10/04/161298/

 

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.

Response: Yes, the Government intends to maintain the same envelope for the General Purpose Projectile as described in Attachment 3 – Ammunition Data. 

83. Question: Is it preferred for awardees’ ammunition to utilize the USG projectile during PTs rather than a surrogate projectile?

Response: The NGSW effort will utilize both the USG General Purpose and Surrogate Projectiles during Prototype Testing. Please see Attachment 9 Prototype Test Outline provides details on the quantity and projectile type used in each test. 

https://imlive.s3.amazonaws.com/Federal%20Government/ID5041233544762060809463086928281536454/NGSW_Industry_Questions_&_Comments_62_-_89.pdf

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.

161. Question: In Attachment 3, is USG interested in other 6.8mm projectile technology that becomes available during the estimated 27 month PON effort?

Response: No, the Government intends to provide the 6.8mm projectile. In the future, the Government may explore other projectile technology.

173. Question: What purpose does the surrogate provide?

Response: The surrogate projectile is designed to mimic the behavior of existing and future combat projectiles.

https://imlive.s3.amazonaws.com/Federal%20Government/ID5041233544762060809463086928281536454/NGSW_Industry_Questions_&_Comments_152_-_281_Part_2.pdf

 

-->Based on these various Q&A's, it seems the Surrogate is distinct from the GP. And the Surrogate is for a 'combat projectile.' Given the already extremely potent 'General Purpose' projectile design, we can reasonably infer that this 'Combat Projectile' is the special AP design. 

 

"Is there reason to think GP and ADVAP are two different bullets?  Has anyone seen the "ADVAP" term being used by the Army or industry since the GP bullet was debuted?"

Per Kitup, source of our 6.8 GP photo:

Two Army officials with knowledge of the new 6.8mm General Purpose Projectile confirms to Military.com that it is very similar to the composition of the M855A1 and M80A1, consisting of an exposed steel penetrator that sits on top of a copper slug and is partially encased in a copper jacket.

https://www.military.com/daily-news/2019/10/27/inside-armys-quest-revolutionary-new-bullet.html

 

Now per Buffman, we've seen Level IV stop M80A1 steel tip at 3400fps from 40' away. Given the AP requirement of NGSW, it strains credulity (even for the Army) that they would be trying to achieve their AP goals with a steel tip projectile.

Meanwhile, previous mention of ADVAP mentions Tungsten:

https://www.thefirearmblog.com/blog/2018/01/29/us-armys-xm1158-advap-round-revealed-tungsten-cored-epr-based-design-cheaper-quicker-produce/

 

Lastly, given the high cost of Tungsten, its hard to imagine the tungsten tip rounds would be used casually for 'general purpose' training use, or use even in combat against unarmored adversaries.  

  • Edited 25 November 2019 2:50  by  gatnerd
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...

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