Originally posted by Guppy35
Of which 93 went to the RAF to go with the 620 Mustang Is that were armed with 2 50 cals and 6 303s.
Definately not the primary RAF Allison Mustang 
57 of that 150 went to the USAAF
Dan/CorkyJr
Correction 2 50cals and 4 30cals (2 each wing).
I'd take the 50/30 combo over the 20mm plane. It'd be a challenge, but in a plane that could actually get you to the point where you can get kills with it.