Is that verified as a real recording? Sounds more like a film script to me.
Firstly, the clarity of voice is suspiciously good to be a radio intercept - and wouldn't crew be on a closed intercom anyway? Second, dramatic external noises such as machine gun fire are very clear and distinct, whereas engine noise is very muted, whereas I would expect the contrary if it were real. Third, what does the order "steady, steady" mean in a real aviation context? Lastly, did crews who flew multiple missions together really address each other as "mid-gunner", "rear-gunner" etc?
Happy to be proven wrong, but my first reaction on listening is that it is lifted from an un-released film script or other dramatised and non-authentic source.