Japan’s Interim Handgun: The “Papa” Nambu

This is lot #646 in the upcoming RIA Premier Auction. It was scheduled for April, but has been postponed – check their web site for upcoming Online Only auctions every month, though!

The pistol colloquially known to American collectors as the “Papa” Number is actually the Modified Nambu Automatic Pistol Type A – an improvement to Kijiro Nambu’s original design (the “Grandpa” Nambu). The Papa was introduced at the Tokyo Artillery Arsenal in 1906, continuing the same serial number range as the Grandpa. It would remain in production there until 1923 with 4600 made, and was also manufactured by Tokyo Gas & Electric from 1909 until 1928 (with an additional 5700 made).

Although marked “Army Type”, the Papa was never formally adopted by the Japanese Army. The Navy did adopt it in 1909 however, and Army officers purchased them as well, as they were required to supply their own sidearms.

The Papa differs from the Grandpa in a number of areas, although the basic mechanics of both pistols are the same. The Papa has a larger trigger guard, swiveling lanyard loop, no stock slot, and a redesigned magazine with an aluminum baseplate. Magazines are not interchangeable between the two models. Production of the Papa ended at the Tokyo Arsenal basically because of the 1934 Tokyo earthquake, and it ended at TG&E after the Army adopted the Type 14 in 1925 and the Navy followed suit in 1927.


  1. The Type 14 does have sort of a nickname. The version with the larger, roughly “pear-shaped” trigger guard to allow the wearing of heavy winter gloves was known to U.S. forces as the “Kiska Model”, because that where it was first encountered in 1942.

    In fact, that modification had first been made in 1940 following combat experience in Manchuria.



    • I have owned a papa nambu, with its original leather holster for many years, never knew to strip down. Thankyou for the demonstration. Finally I can pull mine apart & clean. They are very nice to shoot, & quite accurate I may add for an 8 mm round. Cheers from Australia.

  2. Back in the early 60’s a friend that was working in a sporting goods store tried to get me to buy a pair of Nambu pistols. One was a Baby, the other was a Papa. It was over 45 years ago, but as I recall they were consecutive serial numbers. He thought that this made them unique and highly desirable. I didn’t. Today, I wish I had purchased them but at that time I was only interested in handguns I could shoot and ammunition was a problem. Also, I considered them quite ugly.

  3. Shaped like a Luger, locks like a Mauser, striker taken from any bolt-action rifle, Baroque machining like Austria-Hungary, and then add your native touches like the asymmetrical recoil spring and the trigger assembly. Actually illustrative of its age: at this time cosmopolitan Japanese gentlemen wore kimonos over longjohns (showing at the throat), fedoras or panama hats, and wooden sandals, while smoking cigarettes in holders and carrying English umbrellas in the manner later immortalized by John Steed. Don’t know if they trained with these latter as weapons.

    • British umbrellas as weapons? Don’t remind me of British Army Colonel Alfred Daniel Wintle, who managed to bamboozle his way out of captivity in Vichy France by mentally torturing his guards through means of hunger strike (and then he somehow sawed the bars off his cell wall and escaped in a garbage cart, after which the entire garrison of Vichy French soldiers guarding the prison defected to the French Resistance if only because they were utterly humiliated by Wintle and feared what would happen if they did not defect to the Allied side and if Wintle should appear before them again) . Amongst other things, the colonel never unfurled his umbrella. I would hate to imagine if the old man actually stabbed someone with it during his service as a commando.

      “This umbrella was stolen from Col. A.D. Wintle” (note left in his permanently furled umbrella)

      It is also noted that Wintle was the first self-representing plaintiff to win a civil case by unanimous vote in the House of Lords. To be fair to the colonel, his opponent was a very dishonest solicitor who had apparently messed with a will (of one of Wintle’s wealthy relatives) to make the solicitor himself a beneficiary of the majority of the deceased’s estate (the guy basically got himself a gift of £44,000 just for writing the will).

      But back to the issue of the Papa Nambu. Since the design is clearly not a copy of any design made in Europe OR America, one would have to think Nambu was some hilariously overdramatic mad scientist who drank too much saké before getting near the drawing board. I mean, the recoil spring unit is on the left-hand side and on the outside of the receiver whereas other pistols had the recoil spring above, below, behind (inside the bolt carrier), or around the barrel. And yet the pistol somehow manages to be balanced and handy enough to fend off unfriendly folks at bedroom distance. I could be wrong.

      • Col. Jeff Cooper stated that he suspected that Col. Nambu concentrated on designing the MGs that bear his name and left the pistol design work to his orderly.

        Of course, the Nambu LMGs (Type 96 and Type 99) were, like the Type 92 HMG also designed by Col. Nambu, based on the French Hotchkiss. The Type 99 is often pegged as a ZB-26 copy, but about the only thing it has in common with that design is the top-mounted box magazine. Inside, it’s a Hotchkiss from muzzle to butt. The only major divergence from the Hotchkiss system is the case ejector, copied from the Lewis gun.

        The motivation behind the Nambu pistols and their cartridges (the 8mm being about equivalent in power to a .32 ACP, the 7mm “Baby” round being closer to a .25 ACP) seems to have been a desire to have a 100% Japanese-designed military sidearm to “show the world”.

        In justice, it must be said that the Type 14 (1925 model) has one of the strongest lockups of any service pistol of its era (yes, even compared to the 1911), and in postwar Army Ordnance tests was found to be one of the most accurate when used with good-quality ammunition.

        Its locking system can tolerate considerably higher pressures than the 8 x 22mm cartridge generates. In fact, in his book Pistolsmithing, Maj. George Nonte recommended that rather than trying to find not just 8 x 22mm unprimed cases (they can be made from .38 Special or .357 Magnum cases, but it’s a PITA), not to mention 8mm bullets (no, .32 ACP or 7.63 Mauser bullets won’t work), a better idea was to bore the barrel out, silver-solder a pre-rifled 9mm tube inside it, then run a chambering reamer in to chamber it for 9 x 19mm.

        From the outside the change is pretty much undetectable, and the Type 14 can easily cope with 9mm Para pressures. The magazine will reliably feed the 9 x 19mm rounds with no changes other than a slight relieving of the feed lips at the rear.



        • A Nambu pistol such modified would certanly make for a good Forgottenweapons episode and/or writeup on this very site.

      • “(…)spring unit is on the left-hand side and on the outside of the receiver whereas other pistols had the recoil spring above, below, behind (inside the bolt carrier), or around the barrel.(…)”
        For another automatic pistol with asymmetrically-placed spring see Webley & Scott automatic pistol – see 6th image from top here:

      • “…Since the design is clearly not a copy of any design made in Europe OR America, one would have to think Nambu was some hilariously overdramatic mad scientist who drank too much saké before getting near the drawing board. I mean, the recoil spring unit is on the left-hand side and on the outside of the receiver…”(C)

        General Kijiro Nambu was a fully qualified engineer and a rather talented designer.
        The design of his pistol is a synthesis of parts of the most successful systems of the time, which were rather successfully redesigned.
        For example, he significantly improved the design of the C96 slide, brought the return spring to the side, making it easier and cheaper. He also did the Luger trigger design, further making it safer.
        His works, although they look unusual for Europeans, from the standpoint of technical and technological rationality, for most weapons designers of those years, may well serve as role models and objects of envy.

        • To any rational engineer, production man, treasurer, procurement officer, or pistol user with a Colt 1900 in hand for comparison this pistol is crazy.

  4. Did anyone else notice that the insignia looked something like the Toyota badge? I wonder if there is a connection.

  5. lf thought the design of this gun began before the beginning of last century, layout, compactness and safety features make it ” best service pistol” of initial military pistol development era… Bolt dismounting is made from the front… Not from back like C96 or Colt government test samples until 1909… lMHO…

    • We have a long and very thin firing pin getting SLAMMED by a linear striker into the primer of a cartridge. I think this is similar to the Dreyse needle breakage problem.

    • And the problem was Nambu’s pistol …
      stupid owners.
      Which, without ammunition, just click the striker.
      By the way, exactly the same problem is with pocket Browning and other similar systems.
      And not only strikers and not only pistols.

  6. After last years French throwing stones I didn’t trust that this wasn’t one of Ians April Fools jokes until the end. That was gold.

  7. “…Dreyse needle breakage problem…”(C)

    If I am not mistaken, Draise did not break their needles. The needles were burned and rusted, so they became worthless.

        • I think the problem with the Dreyse needle was more likely due to corrosion. The needle was to be replaced after about a dozen shots. If it is not immediately cleaned of mercury primer products, and no one will do this during the battle, then in the morning it will be possible to paint with a rusty needle.

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