20mm and 30mm mine shells aren't supposed to penetrate far. They rip big holes in the aircraft skin. There is no effective defense against such explosive cannon shells as you cannot armor the aircraft wings and fuselage.
True, i think its more a point of fact that a large hole in the aircraft skin will not in of itself bring a plane down.
To temper the argument, it makes the idea of a plane absorbing 21 20mm impacts more conceivable if the cannon shells never effectively penetrated and hit a vital part.
However, a round that effectively penetrates causing an explosion inside the framing could sever cables or hydraulic lines, impact fuel tanks which explode, or even damage the turbo housing which could also lead to fire, and all such scenarios could end the fight much sooner than a hole(s) in the aircraft skin.
I don't gather that HE rounds are that capable against armored plating either.
In fact, the Hispano testing verifies this, showing only 8mm penetration at 200 yards for the Mk I HE rounds. At slight angles of impact, there is no measurable result on armor.
I think its also why they used mixed belting.
When the Luftwaffe found itself taking on large bomber formations, they had the hurdle of getting effective hits with large caliber cannons while flying inside the effective range of 50 caliber machine gun fire.
Head on attacks were favored because the plane was less protected and firing into the path of the plane meant the added closing velocity would facilitate penetration of the round on impact.
I often wonder what the penetration of the mk103 and 108 was beyond 200 yards?
Jets were said to have used the weapon with more efficiency because their added speed helped fly the shells into aircraft with the added velocity of the jet.
Otherwise, heavily armored fighters like the Sturmbock were developed to fly in close enough to the bombers and get effective hits.
I read someplace where Mayer wasn't even in the area. (substantial proofs given) Makes for a good story being shot up by a Lw ace and surviving.
