Best for Emeric to answer questions on this!

poliorcetes said...

Tell me if I have understood it correctly: in order to maintain compatibility, part of the body of the bullet would act as a neck in the chamber?

If it is the case, then there would be a small gap in the chamber, corresponding to the thickness and volume of cartridge neck, right?

Right.

The bullet is potentially unsupported during a much longer "freebore", so there is a need to mitigate unwanted consequences, but it's not significantly different from a CT round.

gatnerd said...

Could you share some more info about the Neckless Cartridges? I recall reading about them here - but completely forgot everything but the name "neckless." 

The basically the neck of the case is eliminated and the projectile is welded directly into the case body. The result is that the shoulder of the case becomes thicker to support the projectile and the power capacity is somewhat reduced - it is further reduced by the projection of more of the projectile into the case. Now the entire distance from the shoulder to the OAL is available for ogive, with the downside that the lead to the rifling become very long. The 7.62x51 goes from being a battle rifle round to a lighter intermediate round that can handle the longest ogive projectiles. The same is possible in 5.56x45 but the result will be rather low powered.

Just to update this, it looks like True Velocity has a working website now, and claims to have rounds from 5.56 to 14.5mm:

http://truevelocityinc.com/

We currently manufacture 5.56 NATO, 7.62 NATO, .338 NORMA, .50 BMG, and 12.7 x 108 ammunition in our proprietary polymer case design.

Interesting claims are:

-Over 50% case weight reduction (totally believable)

-Weapons remain cooler (something that was hinted at with LSAT)

-Provides substantial flash reduction (this I have no idea about, but would be awesome if true.)

It appears the polymer body is overmolded around the internal metal base. The metal looks to be steel; without some type of shielding aluminum might have the risk of burn through.

I wonder if ZAMAK zinc alloy would work as a base for this type of cartridge? It's lighter/cheaper than steel and can be easily die cast. 

gatnerd said...

 

Just to update this, it looks like True Velocity has a working website now, and claims to have rounds from 5.56 to 14.5mm:

http://truevelocityinc.com/

We currently manufacture 5.56 NATO, 7.62 NATO, .338 NORMA, .50 BMG, and 12.7 x 108 ammunition in our proprietary polymer case design.

Interesting claims are:

-Over 50% case weight reduction (totally believable)

-Weapons remain cooler (something that was hinted at with LSAT)

-Provides substantial flash reduction (this I have no idea about, but would be awesome if true.)

It appears the polymer body is overmolded around the internal metal base. The metal looks to be steel; without some type of shielding aluminum might have the risk of burn through.

I wonder if ZAMAK zinc alloy would work as a base for this type of cartridge? It's lighter/cheaper than steel and can be easily die cast. 

 

I believe the bases are aluminum, although I'm not sure. The polymer body completely covers the inside of the round as per the patent drawings.

I ran this design by Kori Phillips, and she agreed that it was promising - more promising than any of the other polymer composite configurations. I have also heard, although I cannot disclose any details about, endurance testing that was conducted with full auto weapons by a third party, and reportedly the ammunition performed extremely well.

"I believe the bases are aluminum, although I'm not sure. The polymer body completely covers the inside of the round as per the patent drawings."

Thanks man, that's a great catch with the patent drawing - and very promising that they can use aluminum. They should end up being pretty close to LSAT weight with the configuration. 

Now if they can just figure out polymer links to go with it...

Any idea of how this sort of cartridge would reduce muzzle flash?

gatnerd said...

 

Any idea of how this sort of cartridge would reduce muzzle flash?

 

Probably by being more thermodynamically efficient.

Pretty big news for TV and the advancement of polymer cases.

They have partnered with General Dynamics, a much larger defense contractor, and will be providing their cases for the .338 Machine Gun and NGSAR programs.

https://www.thefirearmblog.com/blog/2019/01/23/true-velocity-partners-with-general-dynamics-on-us-armys-next-generation-squad-automatic-rifle/

Looks like we're getting closer to a viable, lightweight case technology being fielded.

Found a nice video on Yotube of TV's presentation at SOFIC.

https://www.youtube.com/watch?v=pUS2_wLlvDY

The two most interesting slides:

That seems to correlate to a 31% weight savings, assuming the rest of the pallet is identical. If its indeed a 31% weight savings that puts it within spitting distance of LSAT's 34% weight reduction, although LSAT has the edge when polymer MG links are factored in.

This is interesting because its the first real indication they've managed to actually get this working down to 5.56. It also shows a serious reduction in chamber heat, potentially allowing for a lighter barrel'd LMG / Automatic Rifle thats still sufficiently resistant to cookoff.

The video also confirmed that General Dynamics is indeed using TV's cases with their .338 LWMMG. 

True Velocity is still plugging away.

Guns and Ammo has two good segments on them. The first covers a visit to the TV factory, and how tight the tolerances are on the cases (holding to 0.001" on the case wall; 0.0005" on the case mouth.) We also see confirmation that bullets are glued into the case mouth, which appears to be essential for these polymer cases vs brass/steel.

https://www.gunsandammo.com/show/guns-and-ammo-tv/videos/181995/325947

And an G&A article:

https://www.gunsandammo.com/editorial/true-velocitys-new-polymer-cased-ammunition/247607

The more interesting video is the on on TV's Facebook, showing a different clip. This shows, for the first time I'm aware of, polymer 5.56 cases being fired. The shooter also describes a dramatic decrease in chamber heat due to the polymer cases (firing 100rd's FA and then being able to put a finger in the chamber right after without burning.)

https://www.facebook.com/truevelocityammo/videos/469202490508619/

Freshly ejected cases are cool enough to be stuck in the shooters mouth: