[Graham Boak]

By "accepting the limitation to 2 cannon" I meant that despite a long-standing requirement for a Fighter Command standard of 4 cannon, the Spitfire continued to be acceptable and developed further with only two. Although the C wing could carry 4 cannon, after the initial production it almost invariably did not. There was one SAAF squadron that fitted 4 for ground attack work, and a solitary(?) example of a Mk.VIII in Australia.

The Hurricane got the 4-cannon because the RAF were looking for a 4-cannon fighter (knowing the Whirlwind was not going to be available in significant numbers) and Sidney Camm got in quickly. After the BoB it was clear that the Hurricane was going to be mainly a bomber destroyer (in terms of UK air defence, and the expected BoB Pt.2 in 1941) so the 4 cannon made sense.

I stand by the comment that it was handling deficiencies and performance (in the widest sense of the word) problems that ruled out 4 cannon on the earlier Spitfires. I believe (as opposed to having seen it discussed professionally) that this would nowadays be recognised as a mild form of inertia coupling, but that was not known about let alone understood at the time - it took the analysis of He162 and F-100 crashes to extend the theory.

The Fw190 fighter bombers certainly did not have the outer guns, nor did the inline-engined versions. The LEMB discussion, from memory, was over one of Priller's aircraft, but perhaps you'd do better to go find it and read what was actually said, not rely upon my possibly-distorted memory. I'm not so sure about such things being done in the final days - more likely to just take and use what you could get, rather than waste time messing about.