'Type VIIB and VIICs carried around 250 rds for the 88mm and about 4380 rds for the 20mm flak gun (or guns)... Later during the war, when the large deck guns were being removed, there was room to carry more anti-aircraft ammunition.'
U-boat Combat Missions, Lawrence Paterson.
Captains could carry additional ammunition if they thought they were likely to need it so tweaking your ammunition levels is well within the bounds of realism. Jim has kindly given us the ability to tweak these values to our own preferred amount.
