...also used as a sniper rifle, here with the (insufficient) scope ZF4. One of the disadvantages of the G43/K43 were the intense muzzle flash and the comparatively short barrel.

Gewehr 43/Karabiner 43

The MG 3 of the german Bundeswehr. Does it remind you of another MG from WW2?

Modern german MG 3

The gun went into production in early 1941, and so probably reached troops starting about 6 months later. This was the "best" anti-tank gun the Japanese had during the war -- the other two main models were of 37mm caliber. A 57mm model was in design. More practically, the Japanese also frequently used the 75mm Type 90 field gun and the 75mm Type 88 AA gun as anti-tank weapons -- and both guns were quite effective in this role.