Our hero was raised on a farm and had little training as a soldier seeing that he was an army cook. Thus, within the first few days of being on the battlefront, he noticed a German plane in hot pursuit of an Allied Kittyhawk and grabbed his gun.
Needless to say, his officers were not impressed by his shooting at an enemy plane independently and he was very nearly court martialled. Read BATTLEFRONT COOK IN EGYPT AND ITALY (available as e-book) to see what happened to his gun.