It's not the 75mm cannon for the B-25H Mitchell, ether Me 109, Hs 129 or Bell YFM-1 Airacuda used this, not even the 105mm cannon on the AC-130 gunship. The plane that used this gun is not in service anymore, but there is one that remain in museum. The main purpose to this gun whas for groundattack, specially to destroy or dammage the enemys invasionfleet, particular the landing craft.