The Japanese were in the process of converting from the Type 38 (6.5X50mm) to the Type 99 (7.7X58mm) at the time WWII started. The 7.7 rifle had a chromed bore and bolt face in order to remain unpitted using the corrosive ammo at the time. Both rifles were workmanlike examples of a bolt action battle rifle and did good service for the Empire, although the Japanese were experimenting with an M1 Garand style rifle towards the end of the war. All that said, both the 38 and the 99 saw extensive use in WWII. The 6.5 was the rifle most carried in China and Mongolia during the pre-WWII battles there.