7.92 x 57mm ID please

Can anybody provide any information as to the identity of this unmarked 7.92mm cartridge? It may not show too well in the scan but there is a red paint casemouth seal and the primer annulus is an unusual grey paint. The primer seems rather oversize for this calibre. All rather unusual features for what I assume is supposed to be a featureless ‘sterile’ load.

Looks like Japanese to me. I am currently on the road so do not have references with me, so cannot remember which load the white p.a. represents.

Have a look in Ken Elks book if you have a copy.


Thank’s Tony. I don’t have Ken’s book unfortunately!! Anybody?

I don’t have Ken Elk’s book either but I have the red mouth band and white annulus listed as armor piercing for the Japanese Navy. I hope that is correct.

I have Ken Elks book :-) and as pbutler says its Jap Navy armour piercing.

7.9mm Type 1 Aircraft Machine Gun Ammunition (Navy)

Your round is an armour-piercing cartridge made for the Navy, as everyone has said. The positive identification as a Navy round is from the large primer, which was only used on Japanese 7.9 types made for the Imperial Japanese Navy. This caliber of ammunition made for the Army has a more normal size primer. These rounds are found in four loadings: Black primer seal for Ball; white primer seal for armour-piercing; red primer seal for armour-piercing tracer; and green primer seal for incendiary. The mouth seal is simply there for water and oil-proofing of the cartridges, and is red on all loads. There are also this type of round with a headstamp from the Yokosuka Naval Arsenal. I have it, and have only seen it, on ball rounds and with one headstamp, “E 3-11 79”. The “E” is the Symbol for the Yokosuka Naval Arsenal. It represents the sound “Yo” and is actually read with the cartridge rotated so that in relation to the Western Alphabet, the “E” is backwards. The “79” is the caliber 7.9. On my round, there is no dot between the two numbers, but the bottom of the numbers run off the edge on that round, so there may have been a dot separating the two figures on the headstamp bunter. The “3-11” represents November 1943 base on the Koki system of dating.

It might be of interest that aside from the headstamped round, which are very scarce, the armour-piercing load with white primer seal seems, to me any way, to be the scarcest loading in this type. I do not have it, and I notice that in Elks book, it is the only loading in this type not shown in the picture. None of these large-primer Navy rounds are really common, by the way.