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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 20/8/21 by EmericD; 42599 views.
smg762

From: smg762

27/8/21

For drag loss, how about a fumer or tracer that retains the speed ...has it been attemppted

roguetechie

From: roguetechie

29/8/21

Yes fumer rounds have been made as small as sub 5mm in the case of the inerdynamics mkr's round. You can find other stuff on fumer rounds at dtic.mil and smallarmsreview

Mr. T (MrT4)

From: Mr. T (MrT4)

29/8/21

Can you post a pic of the 64gr bullet side by side with M855

EmericD

From: EmericD

30/8/21

Mr. T (MrT4) said:

Can you post a pic of the 64gr bullet side by side with M855

M193 / M855 / M856 (fired) / 70 gr VKO / 64 gr "5.56 mm D" / 7N6 / 5.45 tracer.

QuintusO

From: QuintusO

30/8/21

You can see why I recommended 1:6.5 or tighter for that VKO. I wish you'd informed me that you would rather use 1:7, I have other designs for that twist specifically.

Even wobbling all over the place it still did good though.

  • Edited 30 August 2021 17:48  by  QuintusO
gatnerd

From: gatnerd

30/8/21

Both the "5.56 D" and VKO are really lovely; they make the 7n6 look dated and the M193 look like a potato by comparison.

Have you considered doing a 3D printed mockup of the 5.56 Neckless cartridge? It would be cool to have a little white 3D printed case with the real 5.56D projectile glued into the case mouth, as a sort mockup of what a 5.56DxTV case would look like. 

Shitty sketch:

  • Edited 30 August 2021 19:41  by  gatnerd
stancrist

From: stancrist

30/8/21

gatnerd said:

Both the "5.56 D" and VKO are really lovely; they make the 7n6 look dated...

Well, sure.  But, you're comparing precision machined solids to a mass produced, steel-jacketed bullet, which hardly seems fair.

If the "5.56 D" were to be mass produced as a FMJ bullet with steel core and mild steel jacket, would it still be as finely shaped?

Is it even possible to mass produce the VKO in FMJ format?  And why would you want to, since it is unsuitable for the purpose?

EmericD

From: EmericD

31/8/21

QuintusO said:

You can see why I recommended 1:6.5 or tighter for that VKO.

We already had this conversation, but since the 1-in-7" is OK for the M856 bullet (even at -54°C), and that the shape of the M856 requires a shorter twist than the VKO (the center of pressure is much ahead of the CoG on the M856 than on the VKO), I figured that the 1-in-7" was OK for the VKO.

And the 6 DoF computation agreed with me!

EmericD

From: EmericD

31/8/21

The M193 was and still is a (flying) potato, but they needed a short bullet to reach the required 3250 fps +/-40 fps.

More interesting is the comparison between the M856 and the 7T3, the M856 is much longer than the M855 ball, while the 7T3 is shorter than the 7N6 ball, and still produce a visible daylight trace at more than 500 m.

So even with pyrotechnic tracers, we have some space for improvement.

nincomp

From: nincomp

31/8/21

How easy is it to accurately predict the angle of repose for bullets.  Is that angle enough to have a significant effect on the effective BC of a highly optimized bullet?

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