how heavy is the steel core on 556 AP rounds?

smg762 said:

how heavy is the steel core on 556 AP rounds?

Which 5.56 mm AP round?

The P112?

>https://www.linkedin.com/feed/update/urn:li:activity:6986420763545239552/

From the T-Worx LinkedIn. They designed the powered rail system used in all NGSW applicants.

The point of particular note here, imo is the ammunition belt. Showing ostensibly the standard issue 6.8NGSW cartridge. The EPR bullet design is clear and expected. But the use of what appears to be an entirely steel case is very interesting.

Perhaps it turned out that SIG's multipart case design was too complex for mass military manufacture.

I initially thought that this would be lower-pressure practice ammo, but the EPR-style bullet confuses me.  My understanding was that practice ammo would use a bullet with less penetration and ricochet potential. 

I recall a NDIA presentation a number of years ago that discussed ammo weight reduction by utilizing thin-walled steel cases but had seen nothing since.  I wonder if the need for extra strength for the base of the new 6.8 cartridge has suddenly made steel cases much more attractive.

SIG's case design being particularly ridiculous was probably the biggest incentive Lake City needed to finally go through with it. 

Apsyda said:

The point of particular note here, imo is the ammunition belt. Showing ostensibly the standard issue 6.8NGSW cartridge. The EPR bullet design is clear and expected. But the use of what appears to be an entirely steel case is very interesting.

Perhaps it turned out that SIG's multipart case design was too complex for mass military manufacture.

It may be that the multi-part case proved too complex for mass production, but I would note that the T-Worx post does not say the rounds are the "standard issue" cartridge.

Another possible explanation for what appears to be steel cases is that they are dummy cartridges used for display at public exhibitions like AUSA 2022, instead of live ammo.

P.S.  Thank you for posting that photo.  I had wondered how the XM157 fire control could be mounted without interfering with opening the top cover. 

I see that the additional long rail clamps only to the short segment of rail on the top cover, so that the fire control and upper rail pivot with the cover.

Excellent find! 

Heres both images larger:

The cases to me look one-piece, and are black. 

Combined with this picture being taken at a display booth or office (where one generally doesn't want a belt fed machinegun with live ammo) I suspect these are polymer dummy cases with real EPR projectiles.

...

In terms of EPR, its good to see they are nice and pointy and streamlined, which seems to my eye to match the 6.8 EPR prototype we had seen earlier.

gatnerd said:

The cases to me look one-piece, and are black.

Black?  Oh, great.  Now I'm going color blind.  The cases look gray to me.

gatnerd said:

Combined with this picture being taken at a display booth or office (where one generally doesn't want a belt fed machinegun with live ammo) I suspect these are polymer dummy cases with real EPR projectiles.

The T-Worx post said the photo was taken at AUSA 2022, so I agree that they are almost certainly dummy rounds.

However, they do not look like any polymer cases that I've seen.  They look to me more like lacquered steel cases.

They could be steel.

That said, they are black, or darkest dark grey. Note the dark grey of the MG links - about as grey as normal steel case x39 ammo - these 6.8 cases are much blacker then the MG links:

The appear to be about as black, maybe slightly lighter, then the black plastic that makes up the top of the ammo pouch underneath them. 

If this is some sort of lacquered steel, then it's a new lacquer coating then what we've seen come out of Russia or really anywhere I'm aware of. 

It would also just be odd to use steel cases here, as the sort of soft 'cartridge steel' used in Russian style steel case ammo is not appreciably stronger or that much lighter then brass, and would require completely new cartridge tooling then what the US uses (to my knowledge there is no US made steel case ammo).

If it's the high pressure steel like used in the GD prototype cases, that could be very cool. And those externally look to be one piece, unlike the Shell Shock and SIG cases.