Any other sources of pilots removing guns?

[Maxrobot1]

Flipping through the book "Aces Full" by Robert Grinsell, Sentry Books, 1974, there is a section on RAF Squadron Leader Neville F. Duke, 112 Sq.,29 victories.
He transitioned from Mk V Spitfires to Kittyhawks. Regarding the Kittyhawk: "It was easy to fly, maneuverable, carried enourmous amounts of ammunition and had better range than any other fighter in the Western Desert. As a gun platform it was unequalled, and although the Kittyhawk replaced the earlier Tomahawk's two .50 cowl guns and four wing mounted .30s, with six .50 caliber wing guns, I preferred to fly with only four wing guns to save weight and improve performance."
P.19

 

[Elmas]

Of course, firing at minimum range with guns of different calibers you can make them hit all together, but firing at, say 3 or 4 hundred yards? The drop of the bullets of different caliber is not the same at all. I've never heard of guns harmonised in the vertical plane so, probably, many Pilots understood that, off a certain distance, they were hitting or with 20 mm, or .50 or .30, but not with all of them.
Certainly it was not by chance that towards the end of the war most fighters had guns of one caliber only.