u/Umschwung_

nếu thật thì học luật hơn 4 năm chỉ bị để 1 đứa kh bằng cấp tước chứng chỉ hành nghề cũng hơi tội

It came out of nowhere in my tank

Picture is presumable taken around 1950s-1960s somewhere in south vietnam (flag is a good indicator). Before ultimately collapsing in 1975, south vietnam actually had a functional railway but vietcong had a bombing fetish for it so it wasn't very safe to use unfortunately

the 3.7cm is essentially a direct upgrade from the 2cm flak: twice the effective range, higher penetration, and the same fire rate with the trade off of having 8-round clips instead of the usual 20-round mag. Jets can be countered easier with this thing since it has twice the range so you can shoot from a little further which wouldn't be too op since jets are very fast either way.

it would be fairly reasonable to replace the 2cm flak with the 3.7cm flak in BRV simply because jets are way too fast, giving the 2cm flak a very short timeframe to effectively take it down.

Allies also have their own version of the 3.7cm: 37 mm gun M1, 37 mm 61-K