The 20mm cannon used were different in design and priorities. The Hispano Mk.II and the MG FF used on the Bf 109E fired projectiles of roughly the same weight, but the Hispano had slightly higher rate of fire and a far superior muzzle velocity. It was nearly twice as heavy, however, and much longer. Initially both were drum fed, resulting in some unsightly bulges on the Spitfire IB.
The Germans then changed over to the MG FF/M which fired ammunition with more chemical content and less metal, so lighter rounds overall.
The MG 151/20 of the Bf 109F (except the first ones) was the result of modifying a 15mm machine gun to take these 20 mm rounds. Resulting in a good rate of fire, good muzzle velocity, relative low weight, and (in its electrically primed version) it could be synchronised. A much better fighter gun than the MG FF and roughly equivalent to the Hispano Mk.V.
The Bf 109D carried four guns – two in the nose and two under the wings. Bf 109E-1s carried the same armament. The E-3 models, though, were equipped with a 20 mm cannon under each wing, installed in two streamlined blisters along with a 60-round ammunition drum.
The inaccuracy of the above statement may be the result of lack of clarity in the writing, but the point is that the wing guns were IN THE WING. the "blisters" were fairings around the ammunition drum, which had greater circumference than the wing had thickness. The same situation exists in the Spitfire IIb and Vb, and was only resolved in the Spitfire by mounting a cannon with a blet feed for the ammo rather than a drum feed. Also, by the time the Spitfire entered combat, the ring-and-bead sight was replaced in the fall of 1939 with a reflector sight.
The 20mm cannon used were different in design and priorities. The Hispano Mk.II and the MG FF used on the Bf 109E fired projectiles of roughly the same weight, but the Hispano had slightly higher rate of fire and a far superior muzzle velocity. It was nearly twice as heavy, however, and much longer. Initially both were drum fed, resulting in some unsightly bulges on the Spitfire IB.
The Germans then changed over to the MG FF/M which fired ammunition with more chemical content and less metal, so lighter rounds overall.
The MG 151/20 of the Bf 109F (except the first ones) was the result of modifying a 15mm machine gun to take these 20 mm rounds. Resulting in a good rate of fire, good muzzle velocity, relative low weight, and (in its electrically primed version) it could be synchronised. A much better fighter gun than the MG FF and roughly equivalent to the Hispano Mk.V.
The Bf 109D carried four guns – two in the nose and two under the wings. Bf 109E-1s carried the same armament. The E-3 models, though, were equipped with a 20 mm cannon under each wing, installed in two streamlined blisters along with a 60-round ammunition drum.
The inaccuracy of the above statement may be the result of lack of clarity in the writing, but the point is that the wing guns were IN THE WING. the "blisters" were fairings around the ammunition drum, which had greater circumference than the wing had thickness. The same situation exists in the Spitfire IIb and Vb, and was only resolved in the Spitfire by mounting a cannon with a blet feed for the ammo rather than a drum feed. Also, by the time the Spitfire entered combat, the ring-and-bead sight was replaced in the fall of 1939 with a reflector sight.
Interesting article otherwise.