All right, I should probably clarify that the Japanese Type 94 isn’t the worst military pistol I can think of. There are a few Chinese contenders right out front. But it certainly had a cumbersome appearance and a fatal flaw.
A quick history, Kijiro Nambu had been working on a Campo-Giro descended pistol with an external hammer and under-barrel locking block years before the Imperial Japanese Army approached him for a new handgun. The Nambu Type 14’s weak striker and large size was becoming a problem. More importantly it was slow to manufacture. They wanted something small, reliable, quick to produce, and chambered in the standard 8mm Nambu cartridge.
With these goals in mind the Type 94 was actually quite successful. It was small, making use of a very efficient dropping locking block. It was reliable thanks to the internal hammer replacing the previous striker system. Production shortcuts were numerous. The channels required for the lock were not milled out from inside the frame, rather they were milled straight through the frame. Thin steel plates were then staked into place to seal the action. Likewise, the bolt was drilled out from the rear and then welded shut and ground to shape.
These shortcuts on milling ultimately brought about the now infamous problem. A trigger bar runs the length of the lest side of the pistol and sits nested in the frame. The channel milled for it was never covered and nearly its whole length is exposed. This would be a minor issue but the bar does not operate by being lifted or pushed back as in so many other pistols. Instead it teeters, with the front being drawn in by a trigger pull and the back being drawn out, releasing the hammer. I’ve included a top-down animation of the offending bits to help this description.
So that means a stray finger, placing just a few ounces of pressure, just a few short millimeters into the front of the exposed trigger bar’s front results in a discharge. Ultimately though, this didn’t seem to be a major issue for the Japanese soldiers. The manual safety simply covers the rear of the trigger bar, preventing any discharge, intentional or accidental. Moreover, the location of the sensitive spot wasn’t likely to be squeezed so narrowly. I know of no reports of accidental discharge or any complaints in the IJA.
Yes, the gun is ugly, it has an odd little grip, limited magazine capacity, potentially dangerous trigger bar, tiny sights, and a high bore axis. But is was handy, light, went bang every time, and fed standard ammo. Certainly worth a chuckle, but I’m sure we can find worse.