7.7x58 SR Green Primer


#1

From a 30 round Hotchkiss feed strip, there are 29 of the one on the left and the odd one out is on the right. Does the green primer mean anything? Going back through old posts there is mention of green annular seals but nothing about complete coverage of the primer. I also found reference to the pinkish case mouth seal meaning ball. They both have that. Any help on the ID of these would be appreciated.

Thanks,
Dave


#2

Dave –

According to Ken Elks’ latest book on Japanese small arms ammunition, the green primer colour on ball, armour-piercing and tracer Type 92 7.7x58SR cartridges was introduced about 1939 to differentiate them from the Type 99 7.7x58 rimless cartridges that entered service then. So it seems you may have just one pre-1939 round in a loading strip of mainly later rounds.

Elks says that post-1939 7.7x58SR incendiary and explosive cartridges did not have green primers, as they were used exclusively in aircraft MGs and there was no possibility of confusion with the rimless Army round.

John E


#3

John,

Thanks for that information. I’ll have to add the Elks book to the growing list of those I need!

Dave


#4

I may be way wrong here. But I have a complete MG strip of the green primer rounds, and I thought they were Boat tail ball rounds???


#5

Steve,

Good to see you 'round! I have no clue when it comes to the Japanese stuff. Where did you get the info on the green primer=boat tail ID? Did you pull one of yours? Other than JJE’s input, it could indicate a thermo-nuclear warhead for all I know…

Dave


#6

Thanks! I got that from CSA Japanese Ammunition cd. I have not pulled a bullet yet as I want to keep the MG strip complete. If I come across a spare I sure will though and keep you posted.

Steve


#7

My take on this is as follows;

7.7mm Type 89 SR Ball - adopted in 1929 for aircraft MG’s. It had a cupro-nickel 162gn flat-based bullet, pink casemouth seal and no primer markings.

7.7mm Type 92 SR Ball - adopted in 1932 for the Army’s heavy machineguns, using exactly the same cartridge case as above but with a heavier boat-tailed 203gn bullet gilding metal-clad bullet, pink casemouth seal and no primer markings.

When the similar 7.7mm Rimless Type 99 was introduced in 1939 it was thought that the new rimless and semi-rimmed Type 92 might become confused and the green primer colour was applied to the semi-rimmed Type 92 series. As this possible confusion was only a problem when used in the Army’s ground role Semi-rimmed Explosive and Incendiary rounds did not have coloured primers as they were solely for aircraft use and therefore there was little possibility of their being mixed up.

I hope this helps a little although I’ve got to admit I’ve really only laid it out like this to try and get it straight in my own head!
If you’re going to collect Japanese ammo you really do need to get part 1 of Ken Elks book.

Jim


#8

Steve,

It seems that by default, the green primer on the 7.7x58 SR would indicate that it is a boat tail ball bullet, assuming there were no other ball types made after 1939, but the intent of the marking wasn’t to designate that. I would think the round with the unmarked primer shown above could be determined to be a Type 89 or Type 92 by weighing it. Thanks, Jim for adding to JJE’s info on these. Now if I can just get Santa to stick a copy of the Elks book in my stocking…

Dave


#9

Dave,
I think there is no doubt the round pictured on the right with the uncoloured primer can only be a Type 92 as it has a gilding-metal bullet jacket. The earlier Type 89 had a cupro-nickel bullet. Weighing would confirm this but the colour of the bullet jacket is a dead giveaway.
Jim


#10

Thanks, Jim,

Missed the cupro-nickel part of your Type 89 SR description.

Dave


#11

Hi,

This topic came up and was addressed in the “previous” forum.

The green or blue green lacquer applied to the primer in the photo above designates a Type 92 which is a semi-rimmed cartridge. The green lacquer was used on Type 92 primers for ball, AP, and tracer loadings and appeared sometime between 1938 and 1941.

Elks speculated that the green lacquer would distinguish the Type 92 from the newer Type 99 which was rimless and introduced in 1939. The reason this was important was because the Type 99 (rimless) ammunition could function correctly in a Type 92 machine gun, but the Type 92 (semi-rimmed) would not function correctly in the Type 99 machine gun. This also explains why the Type 92 ceased to appear from about 1943. Since the Type 92 first appeared in 1932, there was a period of approximately 6 years where the Type 92 did not have the green lacquer primer. Therefore, the Type 92 could have an unmarked primer or a green lacquered primer, but the lack of the green lacquer would not disqualify a cartridge from being an earlier Type 92.

The Type 92 ball did use a 203 grain GM boat-tailed bullet. The Type 92 was made in ball, AP, tracer, blanks, de-coppering, high-pressure test, dummy, and armourer’s dummy.

I agree with JJE in that both cartridges in the photo above are Type 92, with the non-lacquered primer cartridge pre-dating 1938.

Hope this doesn’t add any confusion.

Heavyiron


#12

Okay then… heres a curly one
Completely green primer, but with a green neck seal and a CN projectile.
The overall length appears to be slightly shorter 78.8mm (top in photo)
I was going to catalog it as a Tracer but the whole green primer AND CN confused me
as I have a green necked CN with no annulus colour cataloged the same, however it also has a
visible knurled cannelure at the neck and a longer overall length 79.8mm (bottom in photo)


#13

I could be totally off-base, but those have the same look of some 7.9 x 57 I have had that were resealed and repacked in Communist China.

John Moss


#14

I found this previous post that also delves into primer colours and the green neck seals in my photo

http://iaaforum.org/forum3/viewtopic.php?f=1&t=6856&hilit=7.7+jap


#15

Craig,
Check to see if your bullet is magnetic. If it is then I think you have a Japanese Type 89 Ball round, captured by the Chinese, and remarked in their ball round colours; i.e. green.
I have the same round (as you found in the earlier thread) and I’ve also got a similarly remarked Chinese AP load with a red primer, green casemouth seal, and a brass bullet.
Jim


#16

Okay then, neither of the projectiles are magnetic in any way.
According to the info given by Elks in his book the type 89 ball rounds are Cupro-nickel clad steel.
And as type 92 ball proj are supposedly GM, then that would lead me back to both rounds being tracer???
My head is starting to hurt now :)


#17

I think I’d have to end my suffering by pulling the bullet and looking inside!


#18

If I remember right - like an elefant which I resembles - i forgot nothing, John Moss is right.
This is simply chinese surplus ammo. It was sold in 1995 in big quantities as shooting ammo.
Wooden crates filled with the cloth covered cardboard boxes containing the 30 rd stripper clips.
I guess the labels where still japanese.