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; 456176 views.
Gr1ff1th

From: Gr1ff1th

29/10/21

Here are some relevant extracts from the study Emeric linked earlier, about the specifics of the effects of chamber misalignment, along with a nice picture of the kind of yaw at 0.54 milimetres for a visual aid

 

  • Edited 29 October 2021 6:52  by  Gr1ff1th
gatnerd

From: gatnerd

29/10/21

Wonderful, thank you, much easier to read.

roguetechie

From: roguetechie

29/10/21

Sounds like going to a more appropriate projectile design could help A LOT...

Hmm who do we know who has projectiles designed for something like this? 

Lolol

Mr. T (MrT4)

From: Mr. T (MrT4)

29/10/21

Would have thought that 0.254mm misalignment is huge to even think of having between the bore and the chamber , till you consider the moving chamber design Textron is using. They are screwed .....

EmericD

From: EmericD

29/10/21

Gr1ff1th said:

Does this mean that you've heard on the grapevine that the Textron is having issues currently, or am I misinterpreting what you're saying?

No, I have no "first hand" information on the Textron offering.

The "anonymous USAMU" claim about the potential lack of accuracy from GD and Textron just reminds me of an old paper I read regarding CT ammo and out-of-center chamber, so I put the link here.

EmericD

From: EmericD

29/10/21

gatnerd said:

Ah, Tungsten EPR I assume?

That was my initial understanding, but I was wrong.

The "smoke screen" on this program is denser than anticipated!

gatnerd said:

That was something I had wondered about awhile back - if they just took the EPR design, and swapped out the steel tip for tungsten, then the projectile would be very front heavy (as opposed to the preferred rearward weight balance.) Also the projectile would be pretty radically different in overall weight. 

Same feeling here when the XM1158 ADVAP was presented.

Replacing the steel arrow of an EPR bullet with a tungsten arrow is going to push the CoG of the bullet in an area unsupported by the shank, inducing a lot of in-bore yaw. So you need also to replace the copper core with a denser alloy to achieve proper bullet balance.

Gr1ff1th

From: Gr1ff1th

29/10/21

Thanks for the clarification Emeric, It can be kind of hard to convey nuance/specific meaning over text on a forum, especially between two unfamiliar speakers.

Gr1ff1th

From: Gr1ff1th

30/10/21

For the sake of this whole program, and the future of small arms in general, I really, really hope that they've found a way to maintain sub 0.1mm tolerances during full auto fire, it's already got acceptable accuracy in the LSAT so by extension it should be fine in the NGSW-AR, It's the NGSW-R Carbine I'm worried about,  I (And everyone here probably) would also like to see a G&A Issue on their entry, seeing as they're the only one to not have one yet, but that's up to Textron obviously

  • Edited 30 October 2021 2:10  by  Gr1ff1th
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