they did deserve great credit for furnishing an operated by gas and blow-back and was maga-
answer to one question that was asked all zinc fed, air cooled and rear seared. It was rela-
through World War II. If the Browning caliber tively light for this caliber, weighing 152 pounds
.50 machine gun was the best of its kind in the with loaded magazine attached. The official rate world, then why did not American engineers of fire was given as 180 aimed shots per minute scale it up to the 20-mm arm we needed so des- and 450 maximum during full automatic. The peratcly at the lime? While we advanced thco- bolt was securely locked during the act of firing ties as to why it could not be done, the Japs noL with gas being used only Lo unlock the piece, only did it but succeeded remarkably well. It had Blow back furnished the necessary energy to a rate of lire of 960 rounds a minute and weighed complete the cycle.
only 84 pounds. Even with the use of inferior The barrel is quickly fastened or detached, metals the components had a life expectancy It is positioned by a set screw in the top of the of 3,000 rounds. receiver acting as a key in a slot on the barrel.
Later a 57-mm cannon, copied after the His- After the interrupted thread bushing is rotated pano-Suiza Type 404, was attempted and was in a sixth of a turn, a spring lock snaps in the rim an experimental stage at the close of the war. of the bushing securing the whole assembly. The
It was known as the H0-401. bolt, gas piston yoke, driving spring, rear buffer,
Discussion of Japanese aircraft cannon with magazine interlock, safety lock, and ejector are any degree of clarity is impossible since they all housed in the receiver. The opening in the were not produced with any object ot her than receiver into which the magazine fits has a spring-
to copy and improvise various mechanisms in as loaded door that snaps shut whenever the maga-
large a caliber as metal limitations would permit. zinc is removed and the gun is not in use. This
One.of the best examples of Japanese develop prevents dust or any other foreign matter from ments was the Model 98 20-mm automatic can- getting into the working parts, non. This was as close as their designers came The gas-piston yoke rides in the slideway ii.
to originality in weapon planning, but was still the sides of the receiver. The locking key that only a combination of features that have been backs up the breech lock is also set in this niern-
in standard use for years. her. The yoke is the carrier for the bolt assembly.
This weapon was so constructed as to be having two tubes that go to the cylinder and adapted to both aircraft and antitank mount- act as pistons. The driving springs arc housed ing, and was successfully tested in 1938 at the in these tubes. The angled surface of the yoke's government arms plant. The mechanism was rear end acts to cam the back of the bolt upward relatively simple and rugged in construction. It into locked position while the rearward thrust
20-mm Automatic Car.non, Model 98, Dual Antitank Mount.
Was this article helpful?