Reduced charge 6,5 mm ammo for Japanese light machine guns


#1

We are all aware of all the funny variations in 7,7 mm japanese WWII ammunition (rimmed, semi-rimmed, rimless, for rifle, for machine gun, etc, etc).

But I didn’t know that the 6,5 mm cartridge also came in two flavors: standard for rifle and reduced charge for light machine gun. At least that’s what I have read in this book: TM-E 30-480, Handbook on japanese military forces, 15 september 1944.

This is quite peculiar because as far as I know, ammo for machine guns, if different from ammo for rifles, has always its charge augmented, not reduced.

The light machine gun was the model 11 (1922), which seemed to be prone to stoppages if full power ammo was used. The gun was fed via a hopper feed which held 6 5-round clips of ammo, and the book says:

Now has anyone heard of this reduced charge ammo marked “G” on the packages? Has it shown up in the surplus market? There were any identifying marks on the cartridge itself?


#2

Per Ken Elks(Part 1, page 41), and I quote:

[i][b]"The need for a 6.5 mm cartridge with reduced charge is said to have begun with the Type 3 Machine-gun adopted in 1914. Allegedly this was due to the necessity of delaying the speed at which the breech opened and so avoiding case head seperation and for the gun to function correctly. The Type 11 LMG of 1922 is also supposed to require a reduced charge in order to function properly.

Ball- Although early packet labels are unknown for the Type 3 MG and Type 11 LMG ammunition, they are certain to have existed. Labelled packets specifically for both Type 3 MG and Type 11 LMG ball ammunition are known from World War II period and although no specimen of the former was available for study, the latter contained cartridges which are, to all extents, the same as the modified Type 38 rifle cartridges."[/b][/i]

A label for the Type 3 MG ammo is pictured. No mention of the “G”.


#3

OOPS! Just found reference to the “G”.

Part 1, page 37-38.

“The boxes containing ammunition with the the three-stake primer crimps are labelled “Type 38 Rifle Cartridge” and many of those seen have a letter “G” in a circle stamped on the packet. This is perhaps from the Japanese (gensoku), meaning “reduced” as has been suggested, but may have a completely different significance.”

It goes on to say that a wartime study disputed the reduced charge “theory” and that only one standard loading existed.


#4

I have seen the label and its explanation, but why would the Japanese use the western “G” on an otherwise all-Japanese label?


#5

Jon - I don’t know why either, but Japanese use of Western Alphabet Letters is not unknown. The Monagram of the Tokyo Gas and Electric Company is not only in our alphabet, but also standing for the English form of the name, TGE, and is stamped on, possibly among other things, Baby Nambu Pistols made by the company. Were it our letters and their words, it would say “TGD” for “Tokyo Gasu Denki.”

Another question could be why ddid (do) they use the Japanese form of numbers for Model Designations and the like, but for numbers in serial, like the serial numbers on firearms, they usually use our form of Arabic Numbers?

I guess this is actually a question in answer of a question, but just pointing out it is not unique to cartridge-box symbols.

John Mosds


#6

This reduced charge story has been going on since WWII.
I can state from my own testing, using cartridges from very expensive unopened original boxes of Japanese 6.5x50sr cartridges, that the reduced charge is a myth.
I found no significant muzzle velocity differences when firing “G” marked box cartridges or non “G” marked box cartridges when using a Type 38 Carbine, a Type 38 rifle, and Type 96 LMG.
I did this live fire testing over 20 years ago, and the cost to do so again today would be excessive.
This subject has been talked to death on Japanese firearms forums over the years. The most likely story is that the Japanese changed powder types and the “G” indicated cartridges loaded with the new powder. The new powder took up less space with in the cartridge case than the older style powder did, thus the “reduced” charge myth was born.
I personally own and shoot both a T96 LMG and a T99 LMG.
The T99 if correctly head spaced and clean will shoot just about anything you feed it; original Japanese production rifle or LMG cartridges, Norma ammo, Hornady ammo, Wolf Gold ammo and what mine is feed most of the time, my hand loads.
The T96 is a different story, in addition to correct head space and being clean; the cartridges for a T96 must be oiled or waxed before loading into the magazine. If not, you will get jammed fired cartridges in the chamber and or torn off rims.
Gregg


#7

Gregg

Your commentary will be printed and inserted between the respective pages of Ken Elks’ book. Did you, by chance, record any of the stats from those tests? I would like to include that info as well.

On a side note, do you know what the F designates on many Japanese artillery shell headstamps?


#8

The 1944 technical manual I mentioned in my first post states on this subject:

A matter of note is that Japanese machine guns generally do not employ slow initial extraction and therefore stoppages are frequent. The Japanese, in order to overcome this, have employed various methods of oiling ammunition either by automatic or gravity oilers, built directly on to the weapon, or oiling ammunition before loading into box magazines. To complicate the ammunition picture even further, they have indicated that their 6.5-mm machine guns normally use a reduced charge, possibly to overcome stoppage and to avoid pre-oiling.

Now, it is not impossible that the reduced charge thing was an urban legend even inside the japanese army, as Gregg says.


#9

when reading 1946 dated Soviet army tech publication on Japanese small arms, i noticed significantly different recorded ballistics (listed muzzle velocities) of the Japanese LMGs compared to rifle… which corresponds quite nicely with barrel lengths of the respective weapons.

The LMG barrels are about 20cm shorter than standard Type 38 rifle barrels, which result in noticeable difference in muzzle velocities.

Just my .02 yen ;)


#10

I seem to recall having read that the magazine loader for the Japanese type 99 LMG was made in versions with the built-in cartridge oiler as well as others, evidently of late manufacture, in which the oil container and oiling pads were deleted. This, if correct, would suggest that oiled ammunition for the 7.7m/m weapon wasn’t a bad idea, but not mandatory. Can anyone confirm this? Jack