Military Guns and Ammunition

Hosted by gatnerd

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; 458681 views.

From: stancrist


gatnerd said:

Cobalt / MARS shared their project - a 140gr @ 3200fps.

Most recently, a video of TV's / GD's bullpup mentioned 135gr @ 3000fps from their 20" barrel at 60kpsi. 

So we know that these companies are designing their cartridges around firing a 135-140gr projectile. Probably this is the 'surrogate' projectile mentioned in the initial NGSW program filings.

It seems rather unlikely there are two government-provided surrogates.

The bullet seen in the Cobalt/MARS round is probably not the surrogate.

The SIG, TV, and Textron rounds have what is likely a 135gr MatchKing.

.270 CALIBER 135 GR. HPBT MATCHKING – Sierra Bullets


From: EmericD


VPMudde said:

A bullet like that is actually even lighter than my estimate, there being more nose cone and less shank.

The original EPR design used a bismuth core. Maybe the XM1186 solved the high temperature problem that plagued the 5.56 mm accuracy?


From: VPMudde


gatnerd said:

That would be worth modeling I think - if the steel EPR is ~125gr, whats the weight of the same projectile with the steel swapped for WC?

The back of this here enveloppe says 160 grains and change (with a density of 11.3)

@Emeric: perhaps, but the old bismuth-tin core M885A1 was pretty much the same shape as the eventual copper core EPR, so I would hazard a guess that that particular alloy's density is, like copper, 8.9 g/cm³. Pure bismuth is slightly more dense (9.8), but being rather brittle it's not a good material to make bullets out of. If they actually did manage a bismuth core bullet that would get you very close to 135 grains, but not quite.

Mr. T (MrT4)

From: Mr. T (MrT4)


While these first-gen FCS look bulky, this is single greatest upgrade to lethality

I imagine Elcan being free of ITAR will corner large chunks of the market.

Msg 7519.1643 deleted

From: smg762


Quick question about the textron 6.8.... am i to understand that only CT rounds can use compressed propellant?

Or could it be used elsewhere -for example- to reduce the size of a 556 round?

And can compressed propellant be combined with high case pressures?



From: renatohm


5.7x28 is bottleneck.


From: gatnerd


Does being a bottleneck have any real effect on feeding reliability when we're talking about pointy, Spitzer projectiles? 

I'd get the benefit for pistol rounds (.357 sig vs .40 using flat tip JHP) but for spitzer, the pointy tip is so much smaller then even a narrow .224 opening that I imagine bottleneck is pretty irrelevant. 


From: gatnerd


Mr. T (MrT4) said:

Elcan being free of ITAR will c

Is that smart optic you're showing the new 'Smart ELCAN?' I had heard they were working on one but have never seen any specs or news on the project since.