The early model Japanese Type 99 Arisaka was by far the most optimistic rifle ever made. The designers envisioned soldiers shooting 175 grain 7.7x58mm rounds and taking down aircraft. The operation of the sights are explained in this excellent video by C&Rsenal

I wonder how many soldiers with bolt action rifles would be required to match the anti-aircraft capabilities of a single heavy or light machine gun, and how much ammunition Japanese soldiers wasted shooting at fast moving aircraft!