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Military Guns and Ammunition

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

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Neckless ammo   Ammunition <20mm

Started 20-Aug by EmericD; 8625 views.
EmericD

From: EmericD

20-Aug

Some preliminary results of our first test of 5.56 mm NL ammo (brass case)

Left from right, the 5.56 mm bullet, the cartridge, the fired case and the 8 mm "balle D" that started everything.

The idea was to scale-down a variant of the 8 mm Lebel "Balle D" (with a slightly secant ogive) and mate this bullet with a 5.56x45 mm case with a neck shortened to ~40 mm (virtually no neck left).

First comment, we used regular IMI 5.56 mm NATO round, pulled the bullet out, removed the powder load (1.66 g of ball powder), removed the neck, put back the powder and the new bullet, then find a way to crimp the cartridge.

Good news, the modified case volume vas enough to keep the orignal powder load, even with the very long (26.9 mm & 63.7 gr) 5.56 mm Balle D.

We fired those rounds out of a Remington bolt action rifle with a 24" barrel.

Muzzle velocity was 963 m/s, and the recorded i7 form factor was 0.84, which is exactly the form factor of the 8 mm version (the i7 of the original "Balle D" is 0.90, but the current version made by TPM is using a slightly secant ogive nose and the FF is 0.84).

So I was wrong, there seems to be no penalty for such small bullet, and its G7 BC is 0.216.

The bullet dispersion was around 3 MoA, not match ammo but OK for military application and pretty good if you consider the very long bullet travel before engaging the rifling.

stancrist

From: stancrist

20-Aug

Very cool, Emeric.  Any plans to try it in a HK416?

EmericD

From: EmericD

20-Aug

Of course, that's the next step! (and also some firings with a trajectography radar).

It seems that we could expect around 884 m/s from a 14.5" barrel, so with a 0.216 G7 BC that would translate to a 900m+ supersonic range and 80% more KE at 600 m compared with M855.

Mr. T (MrT4)

From: Mr. T (MrT4)

20-Aug

Very cool to see these kinds of experiments, i am still holding off on pushing my 6mm to such an extremely short neck , would be interested to see any data on velocity ES ,SD  of such no neck cartridge.

I made a tiny bolt action for suppressed use , but am now also working on a more sporting oriented edition and am trying to get a 6BR performance (out of 26in barrel) out of an wildcated 6mm  from barrel no more than 20in long and Ar15 mag feed OAL.

*overlooked the shortened case to be neckless part , i was considering blowing forward the shoulder until you end with no neck or short neck.But with .223 case that is not quite the option like it is with my Grendel based cartridge.

QuintusO

From: QuintusO

20-Aug

EmericD said:

So I was wrong, there seems to be no penalty for such small bullet

Not to say I told you so, but... ;)

roguetechie

From: roguetechie

20-Aug

Oh man that round is very good looking....

It's so awesome to see this stuff coming to life.

QuintusO

From: QuintusO

20-Aug

Are you ready to re-test my bullet now with the correct twist rate?

EmericD

From: EmericD

20-Aug

QuintusO said:

Not to say I told you so, but... ;)

...But I was wrong and it's a pretty good news.

I'm not going to retest the 556 VKO for multiple reasons (not working in a 1-in-7" twist being the first), but the .338" looks attractive for sure.

EmericD

From: EmericD

20-Aug

Mr. T (MrT4) said:

Very cool to see these kinds of experiments, i am still holding off on pushing my 6mm to such an extremely short neck , would be interested to see any data on velocity ES ,SD of such no neck cartridge.

It's not a viable option for large-scale production, the final round should look like a scaled-down 6.8 mm TVCM.

gatnerd

From: gatnerd

20-Aug

EmericD said:

The idea was to scale-down a variant of the 8 mm Lebel "Balle D" (with a slightly secant ogive) and mate this bullet with a 5.56x45 mm case with a neck shortened to ~40 mm (virtually no neck left). First comment, we used regular IMI 5.56 mm NATO round, pulled the bullet out, removed the powder load (1.66 g of ball powder), removed the neck, put back the powder and the new bullet, then find a way to crimp the cartridge. Good news, the modified case volume vas enough to keep the orignal powder load, even with the very long (26.9 mm & 63.7 gr) 5.56 mm Balle D. We fired those rounds out of a Remington bolt action rifle with a 24" barrel. Muzzle velocity was 963 m/s, and the recorded i7 form factor was 0.84, which is exactly the form factor of the 8 mm version (the i7 of the original "Balle D" is 0.90, but the current version made by TPM is using a slightly secant ogive nose and the FF is 0.84). So I was wrong, there seems to be no penalty for such small bullet, and its G7 BC is 0.216.

Wonderful test and news! This is so exciting, and the results sound great. If this all comes to fruition you will have seriously evolutionized the 5.56 and its future capabilities. 

Couple questions.

-What was the solution for crimping? Were the bullets glued in the case? 

-Is the crimp durable enough in the brass configuration that it could be used in military applications, or does this really need a polymer, mini TV configuration? 

-How was the bullet made? And does there look to be a viable path forward for making these 'mini D's' economically at scale? 

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