Afterwards this feature was removed with the blank rounds magically appearing straight into the rifle without touching the ammo count of the live rounds. Before an update, it used to be simulated accurately with the soldier ejecting a live round and inserting a blank and vice versa.
Acceptable for artillery strikes which can be pre-called and ready, not so much for the bombers unless they happened to be flying nearby specifically for the player's missions. While similar to Insurgency there are some notable differences:
Acceptable Breaks from Reality: Despite the historical setting and being on the realistic end of Fackler Scale of FPS Realism, the game developers have stated that gameplay will come first before realism.
Compare with Hell Let Loose, a similar shooter also set in WWII's European Theater.