Good start Krases - and welcome!
As a seasoned planebucket contributor, can i make a few well intentioned suggestions;
First, try to use real images to facilitate the adding of details like ailerons/flaps, sheet metal joins and access covers etc, as often when you scale down your reference drawings to SB scale you loose the vast majority of that. Detail and accuracy adds credibility.
Second, adding minimal amounts of shading effects can create a heaps better result and give your drawing tons more realism - and its not hard! Take my drawings of the B.20 and B.44 prototypes below.
Yours;
Verses Mine;
As to your weapons choices;
A single engined, monoplane fighter like you've drawn wouldn't have the room in the nose for 20mm Cannons like the WW2 Hispano - it's all engine and props up front with little room for anything else - you could perhaps mount them in the chin of the aircraft, directly below the engine, or on the flanks of the fuselage just forward of the cockpit, but the best option is in the wings/wing roots. The only WW2 single-engine Allied fighters i can think of off the top of my head to successfully carry nose-mounted armament was the Bell P-63 AirCobra/KingCobra series fighters, and then only because the engine was mounted behind the cockpit in the fuselage, allowing the cannon to sit on the center-line and fire through the prop-spinner itself.
Nose-mounted 20mms on the B.20 analogue is quite plausible, but a rear-facing 20mm is a bit rich. Most crew-served armaments on night-fighters and bombers were rifle calibers, with some mounting up to 30 cal or 50cal MGs. If you want heavy-metal, maybe go for a quad 30cal turret in the tail, and single 50cals for each of the broadside observation blisters/turrets. 20mms in the nose is great but their practical utility in attack would be limited. Planes like the B.20 were designed as big, lumbering patrol bombers, they used bombs, rockets and depth charges as their primary offensive weapons against U-boats and surface targets - far too slow and vulnerable to AAA flak to make strafing with MGs and cannon a reasonable offensive option. If you're looking for an attack aircraft for surface targets, I suggest you play around with the Bristol Beaufighter, De Havilland Mosquito, A26 Invader or A20 Boston/Havoc.
Practice makes perfect - keep up the good work champ
Look forward to seeing more of this AU in due course.
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