And both were just about completely worthless as AA weapons with some experts questioning why they even bothered with the effort of giving it a high elevation at all.

Tk3997 said:

And both were just about completely worthless as AA weapons with some experts questioning why they even bothered with the effort of giving it a high elevation at all.

Really? Because American 5-inch guns were actually quite useful as long-range AA weapons. What caused the Japanese 5-inchers (sorry, 12.7 cm) to be worthless?

Eboreg said:

Really? Because American 5-inch guns were actually quite useful as long-range AA weapons. What caused the Japanese 5-inchers (sorry, 12.7 cm) to be worthless?

A slow training speed (time to aim the gun) worsened by the need to lower the gun barrel to load (the power ram on the USN 5"/38 allowed it to be loaded at any angle) and the fact that it was a shell-and-powder-bag setup instead of a complete cartridge lowered rate of fire significantly though the sited rate varies greatly across publications. I'm pretty sure the shell fuzes were set by hand with a best-guess to the range of detonation compared to the Allies' radar fuzed AA shells. That last one's heresay and hinted at on NavWeaps ("3) Fuzes were set by hand on the loading tray.") but I didn't dig deeper into it. NavWeaps also points out that though one publication sites a horrid 4.4-round-per-minute rate of fire, the ammunition supply would support 10-rounds-per-minute and it'd be nonsensical to make a supply line double the efficiency of the maximum fire rate, so it was probably closer to 10. A 5"/38 gun with an ammo hoist fired somewhere around 15-22 rounds-per-minute.