gatnerd

Military Guns and Ammunition

Hosted by gatnerd

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

  • 3361
    MEMBERS
  • 191243
    MESSAGES
  • 6
    POSTS TODAY

Discussions

NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 555300 views.
Farmplinker

From: Farmplinker

22/11/19

I know that suppressor works great from reporting on it; but man is it ugly!

poliorcetes

From: poliorcetes

23/11/19

Interesting article in Russian:

 

https://pereklichka.livejournal.com/1790278.html

 

At the end, what really matters about NGSW is armor penetration. And as some fellows said, circa 4200J could be not enough...

gatnerd

From: gatnerd

23/11/19

"At the end, what really matters about NGSW is armor penetration. And as some fellows said, circa 4200J could be not enough..."

What will really make or break the AP requirement is projectile design. 

We're really left with 2 options. 

1. The Army hasn't seen Buffman's testing and is unaware of how tough current Level IV really is vis a vis M993 (130gr M993 stopped @ 2850fps by IV.)

2. The Army has developed a substantially better AP projectile technology then current M993. 

In terms of Option 2, several theories.

2a: Rather then traditional Tungsten Carbide (WC), the Army is using Tungsten Heavy Alloy (WHA), which is denser and better penetrating.

2b: The Army is using a better / new WC/WHA sintering method, making the penetrator less prone to shattering/deforming when impacting the Ceramic.

2c: The exposed Tungsten penetrator of the new projectile substantially boosts penetration vs a traditional jacketed penetrator like M993.

2d: The new AP projectile uses a different material then copper for the base. This material, through superior acoustic impedance, allows the base to synergize with the tungsten tip, and perform similarly to a full length tungsten penetrator. Ie a 15mm Tungsten Tip + 20mm Material X penetrates like a 35mm long Tungsten penetrator.

2e: The new AP projectile is not an EPR like M80A1/M855A1, but is a new style of bullet called Aeroshell. This pairs a full length WHA penetrator with a polymer jacket. Whereas M993 is a 130gr projectile with 90gr tunsgten core, this would be a 130gr bullets with a 120gr full length core:
https://www.armytimes.com/resizer/3K7OF4GLPRnT3np36pPIXb0dIPY=/600x0/filters:quality(100)/arc-anglerfish-arc2-prod-mco.s3.amazonaws.com/public/4J6OFQLIABCFZBVWA5FK53ONG4.jpg

If 2 is true - they've made a better AP projectile - then the answer is likely found in some combination of 2a-2d.

 

Currently, Nammo has only managed a pretty modest improvement over M993...

 

 

 

Red7272

From: Red7272

23/11/19

poliorcetes said...

At the end, what really matters about NGSW is armor penetration. And as some fellows said, circa 4200J could be not enough...

My feeling too is that the 6.8 is not the solution. Going for weird penetrator technologies and brute force will work for special forces but not for massed armies. They will lack the training to manage the heavier recoiling weapon and the cost in rare materials will become prohibitive. And given that we are only at the beginning of the cycle of body armour development the 6.8 will not be enough, probably by the time it is fielded.

Given the objective is to incapacitate the target, projectiles that interact with the armour by flashing might be an option, especially if it behaves as a ball round elsewhere. That will also give the shooter an indicator in regards to penetration. Coupled with a compact thermobaric grenade launcher that might be a more widespread solution than tungsten and brute force.

renatohm

From: renatohm

23/11/19

I've been saying that all the time - the solution for body armor is NOT kinetic energy but chemical energy.

A projectile with a flash may be okay for some uses but still won't work for body armor.

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

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...

TOP