[Karaya]

The MG151 was belt fed and for the 15mm in F-2 motorkanone there was a 200rd box. When increased to 20mm in F-4 there was a 150rd box.

The F-4 and later 109s could carry a maximum of 200 rounds of 20mm as well, the increase of calibre of the round did not mean a reduction of stored ammunition with the Mauser. This can, for example, be seen in the "Ladeplan":

Here for a Bf109F-4 Trop



Says 500 rounds for each MG17 and 200 rounds for the single MG151/20