From the Rock Island Arsenal blog

Of all the things you own that were made in Japan, we’re betting a Nambu pistol isn’t one of them. The Nambu pistol series was developed by Lieutenant General Kijiro Nambu in 1092, who claimed the design for Japan, but it looked a lot like the Mauser C96 Japanese officials admired while touring Europe.

The Rock Island Arsenal Museum has on display two pictols, the Nambu Type 14 and the smaller Type B “Baby” Nambu. Both are semi-automatic, using the recoil of the first round to provide the energy to move the next round into position. The Nambus have a skinny barrel and one-piece frame, were loaded by magazing instead of a spring-clip option, and had an effective firing range of about 55 yards.

Baby Nambu Pistol

The Baby Nambu was smaller, firing 7mm rounds. It held 7 rounds in the magazine, as opposed to the 8 in the Type 14. The Nambu magazines slid into the bottom of the pistol and are not shown in the video. The Baby Nambu was supposed to be a sidearm for Japanese officers. Like the British officers, the Japanese were expected to purchase their own pistol but it was priced out of reach for all but the most high-ranking and thus became a status accessort. Only 6,000 were made and the Japanese army never adopted them as an official sidearm.

Such was not the case with the larger Type 14 which made it into the Japanese inventory. Based on the original Type A “Grandpa” Nambu, it was issued to NCOs in 1927 and could be purchased by officers. The Nambu Type 14 is prized by the Japanese-style production date stamped on the right side. Most Type 14’s are engraved wiht the current year of Hirohito’s reign and the name given to his reign. Ours is 17.12, adding 17 to the year 1925, with the last digits as the month of production, which would be December of 1942.