gatnerd

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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NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 505945 views.
EmericD

From: EmericD

27-May

Guardsman26 said:

Emeric, I am not a ballistician, but what do you estimate would be the chamber pressure of a 6-7 gram 6.5 mm bullet fired from a 6.5x49 mm Creedmoor cartridge at 3,000 fps / 914 mps?

The 264 INT (the child of the 264 USA) is pushing a 6.7 g EPR bullet at 3010 fps out of a 20" barrel (and 2850 fps from a 14.5"), while staying below 62 kpsi.

  • Edited 27 May 2022 14:35  by  EmericD
Guardsman26

From: Guardsman26

27-May

How interesting. I was not aware of this cartridge. Can you point me towards more technical information about it. 

I am going to contact you separately to discuss NGSW!!! 

gatnerd

From: gatnerd

27-May

Great picture! I’d also like to know more about the .264 INT, and how it compares to 6.5C.

nincomp

From: nincomp

27-May

Disassembly of SIG Spear.

  Note, the "PDQ" that is mentioned a couple of times is the aftermarket "PDQ ambidextroud-bolt release" that Karl has used in the WWSD (What Would Stoner Do) carbine.

https://youtu.be/hO4IKxECNzI?t=351

gatnerd

From: gatnerd

27-May

The PDQ is such a lazy implementation of ambi.

LWRCi and LMT have a much better, true ambi lever that is both bolt catch and release, and have for the last 6+ years. 

BruhMomento

From: BruhMomento

27-May

https://www.youtube.com/watch?v=hO4IKxECNzI

InrangeTV's MCX Spear disassembly + Thoughts + Live fire

stancrist

From: stancrist

27-May

stancrist said:

       Guardsman26 said: My understanding is that SOCOM units deploying with 6.5 and 6 mm weapons have an EPR loading. 

Very interesting.  A pity we can't get a photo of either EPR bullet.

It looks like we got a photo of the 6.5mm EPR.  https://forums.delphiforums.com/autogun/messages?msg=7519.2783

Thanks Emeric!

stancrist

From: stancrist

27-May

Guardsman26 said:

I am going to contact you separately to discuss NGSW!!!

Well, that's rude.  The rest of us are interested, too.  stuck_out_tongue_winking_eye

stancrist

From: stancrist

27-May

gatnerd said:

Great picture!

Indeed.  So I guess now we know that the 6.5 EPR being used by SOCOM is 103 grains?

gatnerd

From: gatnerd

27-May

stancrist said:

Indeed.  So I guess now we know that the 6.5 EPR being used by SOCOM is 103 grains

I suppose so? 

Previously in this thread, a member here kindly analyzed the 6.8 EPR and figured the projectile weight had to be ~120gr, not the 135gr we had assumed. And thats with a nice long projectile.

So then it would stand to reason that a 6.5 EPR based on a comparably nice form factor would be lighter then the 6.8. A reduction of 17gr weight seems reasonable given the reduction in diameter and (probably) length. 

Notably Nathanials 6.8 and 6.5 EPR design - also a very fine shape - ended up with a 125gr 6.8 and 108gr 6.5 when using the same form factor. 

https://www.thefirearmblog.com/blog/2017/09/09/romulan-vulcan-preference-driven-vs-process-driven-design-field-small-arms-ammunition/

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