Is it Toggle Month, or what? Readers of TFB have so far been treated to several posts in April on the famous toggle-locked Luger pistol, but the fun’s not over yet! In the 1930s, the Japanese were – like many major powers at the time – looking to replace their bolt-action Type 38 rifles with more modern selfloading weapons. During this time, John Pedersen, designer of the toggle-retarded blowback Pedersen rifle series, traveled to the islands to demonstrate his design to Japanese Army officials. Pedersen did not successfully sell his rifle anywhere (despite it being a world-class design), but Japanese arms manufacturers could not quite let go of Pedersen’s ideas. Ian McCollum of the Forgotten Weapons YouTube channel takes a look at two such rifles designed and manufactured by Japanese companies, but based on Pedersen’s excellent rifle. These are the Tokyo Gas & Electric rifle, and the Nippon Special Steel rifle, videos on both being embedded in that order below:

These two rifles differed in their exact method of operation. The Tokyo Gas & Electric design’s action is a straight clone of John Pedersen’s toggle-retarded blowback design, where pressure builds against a carefully designed knee joint until it exceeds a threshold and operates the firearm. This comes with the downside of needing lubricated ammunition or a fluted chamber to work properly, neither of which the TG&E rifle possessed for whatever reason. The result was a firearm that began to have extraction and ejection problems if fired for long periods of time, something that Pedersen solved in his rifle with a very excellent design of wax-coated ammunition.

The Nippon Special Steel rifle, on the other hand, uses a kind of action not often seen in small arms. Unlike the Pedersen or the TG&E rifle, the NSS rifle uses a fully locked toggle, like a Luger, where no amount of pressure will force the toggle open. However, unlike a Luger, but like a Pedersen, the barrel is fixed. To unlock the action the NSS engineers added a thin, forward-moving gas piston under the barrel, which pulls forward under gas pressure from a port drilled in the barrel, kicking against flanges protruding from the toggle and forcing it open slightly. Unusually for a small arm, the piston does not drive the action itself as it would in a modern gas-operated design, but only unlocks it. Cycling was accomplished by the residual pressure of the fired round in the chamber, like a retarded-blowback design. This design solved the problems of needing flutes or lubrication, as the cartridge remains fixed in the chamber until pressure is sufficiently low, and reportedly worked very well.

The distinction between the two types of operation is worth noting. George M. Chinn, who wrote a seminal volume on machine gun operation, would call the TG&E rifle a “retarded blowback” design, a label he would likewise give to the H&K G3, FAMAS, or Pedersen rifles, weapons all commonly referred to in the small arms world as “delayed blowback”. Confusingly, the unique operation of the NSS rifle (the fundamental principle of which is much more common in autocannon design than it is in small arms) would be regarded by Chinn as “delayed blowback”, a term I’ve so far avoided using in reference to it to avoid confusion in my readers. Chinn’s basic distinction between these two types of operation is that a “retarded blowback” weapon is never fully locked, while a “delayed blowback” weapon is.