yeah, maybe this could actually be some new historical thing and someone digs up something cool. need to ask one of the real u boat men. but in the gwx manual it says that its way faster. (page 55 i think)
the flack gun was magazine fed. and the mg34s (some u boats had 2 along with 2 flak guns, a deck gun and heavy flack up back
) that some u boats had where belt fed. im not sure whether there where any u boat weapons drum fed.