Original & Collectible Ammo

The Japanese used three different rounds in their principal service handguns, all of them uniquely Japanese: 8mm Nambu, 9mm revolver and 7mm Nambu. There is information about these calibers in Cartridges of the World, Revised 5^th Edition by Frank C. Barnes, editor (DBI Books, Northbrook, Illinois, 1985) on pages 173 (7mm Nambu) and 182 (8mm Nambu). Oddly, the book does not include 9mm Japanese revolver, though almost ten times as many guns were made for it as the 7mm Nambu cartridge. The Japanese made several other foreign calibres, especially .32 ACP. These were principally for pistols privately purchased by officers, although a few Japanese-made guns were also chambered for rounds like .25 ACP or .32 ACP.

In the photo above, the cartridge on the left is a 7mm Nambu for the Baby. The bottle-necked cartridge to the right of that is an 8mm Nambu for the Type 14, Type 94, Papa, Grandpa and a few others. Second from the right is a 9mm Japanese revolver (for the Type 26). The one on the far right with the red band is a Japanese-made .32 ACP, mostly used in imported pistols but also in some domestic ones like the Hamada.

8mm Nambu

This was the standard Japanese service round, used in the Grandpa Nambu, Papa Nambu, Type 14 and Type 94 pistols, as well as the Type 100 submachine gun and a few other small volume pistols. The original 8mm Nambu ammo came in 15 round boxes, two of which would fit in the pouch on the holster. These boxes are very scarce. I paid C$3 (US$2.16) for one original round at a gun show in Calgary in April, 2003, and have bought others for as little as C$1 (US$.75) but I have seen people try to sell them for as much as C$10 a round (US$7.20).

The 8mm Nambu round looks a little like 7.65mm Luger (also called .30 Luger). At the far left are two original 8mm Nambu rounds, one with a copper jacket and one with cupro-nickel (silver-coloured). The slightly shorter round next to it is a W.R.A. 7.65 Luger round. The second one from the right is a little longer. It is a 7.63 Mauser / .30 Mauser round used in the Broomhandle Mauser. At the far right is a Yugoslav 7.62mm Tokarev, also called 7.62 TT or .30 Tokarev. It is basically a hotter loading of the 7.63 Mauser. US and Canadian dimes as well as a ruler are included in this shot and the other comparisons below for scale.

Ballistically the 8mm Nambu is very similar to the .380ACP, even though it is much bigger in external dimensions. Both fire a bullet of around 100 grains at muzzle velocities of around 1,000 feet per second, give or take a bit.

Here are seven different 8mm Nambu rounds. From left to right: cupro-nickel bullet with small punch-crimp on neck; cupro-nickel bullet with large punch crimp on neck; copper jacketed with large punch crimp on neck; dummy/practice round (see below); early post-war B&E rounds from the USA (see below); 1980s Midway round (note punch crimp); current production OWS round (see section on “Shooting Ammo” re the last two).

Here are the heads of six 8mm Nambu cartridges. The two on the far left are original Japanese rounds. Third from the left is the dummy round (note darker, copper-coloured “primer”). Third from the right is the B&E round, then a post-war Midway round (now discontinued). The one on the far right is a current manufacture round from Old Western Scrounger. They use cases from Huntington Die Specialties, hence the “H.D.S.” on the headstamp.

The dummy round has a groove in the projectile and knurling around the cartridge case.

As noted above, the practice round has a darker, reddish, copper-coloured primer (right) as opposed to the yellowish brass coloured one on regular rounds.

This is a late manufacture (January, 1945) copper-jacketed round from a full box of ammo I bought.

Here’s something I didn’t know until Jim Brown (co-author of the Derby & Brown book) sent me this example. The priming compound inside the primer cup had a thin foil covering on it to protect it during manufacturing. This primer was removed from a WWII-era Japanese 8mm Nambu round using hydraulic pressure. It got slightly deformed in the process. Like all such primers, it is Berdan.

As long as we are looking at the insides of the cases, let’s go all the way. A cartridge collector friend of mine sectioned these two original Japanese 8mm Nambu rounds. The one on the left is the earlier, cupro-nickel-jacketed type, while the one on the right is the later copper or gilding-metal jacketed type. Bullet weights were 6.59 grams (=101.7 grains) for the cupro-nickel and 6.54 grams (100.9 grains) for the copper/gilding metal rounds. Powder weight of .29 grams (4.5 grains) was identical in the two rounds. Note the interesting shape of the powder grains. By the way, don’t copy the load of 4.5 grains unless you have a stock of this exact WWII Japanese powder and these exact bullets and cases!

Besides the original Japanese rounds, at least one other type qualifies as collectible. In the early post-war period there were more war souvenir Nambus than there was ammo, so in 1948 two enterprising residents of Minneapolis, Robert E. Bard and Osborne Klavestad, got some backers and went into the business of making 8mm Nambu ammo under the B&E brand. The B&E rounds were highly unusual in that the cartridge cases were turned, not drawn in the usual way. Ten-foot lengths of brass rod were fed into a six-spindle screw machine that turned out a completed case every five seconds, or 720 per hour. The bullets were also unusual. Lead wire was cut to length, then formed in a die and plated with a copper alloy. The company only operated for a few years and their cartridges are too scarce to shoot today. For more information on B&E rounds, see the source of the details in this paragraph, i.e. “Handload the 8mm Nambu” by Larry S. Sterett, pp. 161-163 of the Handloader’s Digest, Sixth Edition (1972).

This headstamp doesn’t show up very well, but across the top it says “NAMBU”. At 9 o’clock is the letter B and at 3 o’clock, E. At the bottom is MPLS (a reference to the fact they were made in Minneapolis).

This is a 50-round B&E box from a friend’s collection.

(Photo courtesy of the Dale Crabtree Collection)

This is a shot of the side of the box.

(Photo courtesy of the Dale Crabtree Collection)

9mm Japanese revolver:

This round was used only in the Type 26 revolver. It is similar in size to a .38 S&W. The ballistics are like a very mild .38 S&W load. The cartridges are NOT interchangeable. The rim on the 9mm round is much thinner and the chamber pressure is lower than most .38 S&W loads. Here is an original 9mm Japanese revolver round next to two .38 S&W loads, a recent commercial Remington with 145 grain bullet and an older Canadian Dominion Armories military load with 178 grain bullet.

Again, the two original rounds on the left have no headstamps, while the two on the right are both post-war Midway ammo (now discontinued).

Here is a 9mm round I had a friend section for me. Note that the powder looks like the same as was used in the 8mm rouns above, and also that there is a cardboard wad in between the bullet and powder. I had not read about that wad being present in any of the references I had read.

7mm Nambu:

Here are four slightly different variations of 7mm Nambu cartridges. The one on the far right is Thai and has a copper-jacketed bullet. The other three are Japanese and have cupro-nickel jackets (silver coloured). They differ mostly in the crimping. The first one on the left has a tiny punch crimp (dead centre near the top of the cartridge case). The next one has an overall press crimp that leaves no visible marks on the case. The second one from the right has a type of press crimp that leaves a tiny raised vertical line between the spots where pressure was applied. It is also noticeably shorter.

This shot shows that the four cartridges above have no head stamps. Japanese pistol cartridges didn’t have head stamps at all; some Thai ones had weak head stamps, but there’s no trace of them on these rounds. The Thai round on the far right seems to have a darker line around the primer, perhaps from some kind of sealant.

Here is a Thai 7mm Nambu round on the far left with some others for comparison. Just to the right of it is a Geco .32 ACP (7.65 ACP) round and a Remington .22 Long Rifle. At the far left is an empty brass casing for .30 M-1 carbine. The two have the same head diameter and one can make 7mm brass from the US cartridge (see below).

Ballistically the 7mm Nambu (left) is comparable to the .32ACP (right). It fires a lighter bullet at higher velocity, but their muzzle energy is about the same. It is certainly better then the .25ACP (second from left), which is what some officers probably would have ended up with in a small handgun (Japanese officers carried a variety of privately purchased foreign handguns including especially a lot of Mausers in .25ACP). A .22 Long Rifle cartridge (second from right) is also included in this shot for comparison, but strangely it seems the Japanese never used this, even for training.

A cartridge collector friend sectioned this 7mm Nambu round for me. It is the “standard” Japanese type with cupro-nickel-jacketed bullet. The bullet weight was 3.58 grams (55.25 grains), and the powder charge weighed 0.18 grams (2.8 grains). Of course, you should not use this powder charge unless you have the same powder the Japanese used as well as the same cases and bullets. Note that this was a finer-grained powder than in the 8mm Nambu sectioned rounds shown above.

.32ACP

This was probably the most widely used “foreign” calibre and was produced by the Japanese for use in imported pistols privately purchased by officers as well in domestically made guns like the Hamada. The Japanese called .32 ACP “cartidges for medum-sized Mauser-type pistol” due to the popularity of the Model 1914/1934 Mauser pocket pistols as private purchase sidearms among officers. Here are two original Japanese .32 ACP rounds.

Again, no headstamps.

.44 Russian

The first modern handgun adopted by the Japanese was the Smith & Wesson Model 3 revolver in .44 Russian calibre. It was the official handgun of the Imperial Japanese Army from 1878 to 1894, and of the Imperial Japanese Navy from 1878 to 1909. Between 1878 and 1908 approximately 16,000 Smith & Wessons were imported. Some were still in service at the end of WWII and were brought to the USA as souvenirs after Japan surrendered.

The .44 Russian is basically a shorter version of the .44 Special, which in turn was lengthened further and became the legendary .44 Magnum many years later. Original Japanese .44 Russian cartridges are quite scarce. Much of the .44 ammunition left at the end of the war had already deteriorated to the point it would not reliably fire. The collector who sold me the one I show below said he recently discovered there are actually two variations. The most common one has a brass case that is drawn in the normal fashion, but some appear to have been turned based on machining marks on the cases. This one is the standard drawn type.

Here is my Japanese .44 Russian round.

Here it is on the left with a n American U-M-C .44 Russian round on the right for comparison.

Once again, there is no headstamp.

Other Calibres:

The Japanese made ammunnition in several other pistol calibres to supply the private purchase weapons of their officers. Among these were .25 ACP, 7.65 Luger, 7.63 Mauser, .380ACP and 9mm Parabellum. However, these rounds are even rarer than the .32ACP and .44 Russian shown above.

Books:

Almost all the reference books on Japanese handguns cover the ammunition, with the new Derby & Brown book probably having the best coverage. Books on ammunition are somewhat less helpful, offering little coverage of the handgun cartridges.

In July, 2003 I received a copy of Japanese Ammunition, 1880 to 1945 by John Elks (1981: publisher and place of publication unknown). Unfortunately it has very little information on handgun cartridges (pp. 7-9; most of it is about rifle and heavy machine gun ammo up to 40mm). The text also has several errors with respect to the handguns themselves, although in fairness this may have been the state of knowledge at the time the manual was produced over 20 years ago.

In March, 2004 I obtained a reprint of a March, 1953 US Army Technical Manual TM 9-1985-5, Japanese Explosive Ordnance (Army Ammunition, Navy Ammunition). It makes only brief references to the 8mm and 9mm handgun cartridges on pages 277-278.

Last updated: December 3, 2005. All contents are copyright Teri unless otherwise specified and may not be used elsewhere in any form without prior permission.

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