The MK 108 was pretty useless against anything with armour. It was devastating when it exploded within aircraft structures. This from my next book:
"The 30 mm HEI M-Geschoss, fired from an MK 108, was also tested. Unsurprisingly, ten rounds fired at a Spitfire fuselage resulted in a score of three immediately lethal, seven probably lethal. Eleven rounds fired at a Blenheim achieved the same results, plus one doubtful. It was noted that the ammunition did not have much effect on heavy bomber fuselages (presumably because of the large volume for the explosion to dissipate into), but inflicted serious aerodynamic damage to the wings by blowing off the surfaces, and that the incendiary content was very effective in starting fires. German tests reflected these results, and also revealed significant differences in the effectiveness of the mine shells depending on the construction of the aircraft. Stressed-skin alloy monococque structures were most vulnerable to being blown apart. Steel structures clad with thin aluminium were less affected as the cladding quickly split, releasing the pressure before it had much time to damage the structure, and fabric-covered structures were damaged least of all. It was not only the blast which inflicted damage; after the war, the Americans test-fired an MK 108 HEI shell into the tail of a B-24 at a typical angle, characteristic of a tail interception by an Me 262. The "spray" pattern of very high velocity, very small fragments cut most if not all of the control cables and many of the longerons. It was assessed that the tail would have separated if the plane had been in flight; a performance which made a great impression on the observers."
Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website:
http://www.quarry.nildram.co.ukMilitary gun and ammunition discussion forum:
http://forums.delphiforums.com/autogun/messages/
