Rate of fire for the Flak 18? Not a problem:
As taken from Handbook on German Military Forces
Length of tube: 10 feet 8 3/4 inches
Effective ceiling: 5,000 feet
Max horizontal range: 7,200 yards
Rate of fire: practical 80 rpm, sustained 220 rpm.
Muzzle velocity: 1,690 feet/sec
Elevation: -5º to +85º
The elevation is for the ground gun, not the SP variant used in the Ostwind. The rate of fire I've got lists only 80 practical, but another book states 220 rpm. While the Flak 43 can fire 150 rpm practical, 250 rpm theoreticaly.
Fast fact: only 40 Ostwind vehicles were ever made. [German Tanks of WW2]
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