The German Minengeschoß rounds introduced a different manufacturing technique: A thin shell was drawn, in the same way as a cartridge case is drawn. This resulted in a much larger explosive capacity for the same calibre, and became widespread after the war. It is commonly assumed that HE ammunition is really effective only in calibres of 20mm or larger, but it was also made for 12.7mm and even rifle-calibre weapons.
These are the belt compositions for fighters, used against air targets, as given given in a German manual, published in in 1944. (Ref. 204.) Note that these were more or less advisory: Local commanders were encouraged to determine the armament mix that suited them. (Note I am only posting for the 20mm and 30mm, if you want more info on other gun types go to:
http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-am.html)
20 mm (MG-FF, MG 151/20)
2 Minengeschoß m. Zerl.
2 Brandsprenggranatpatronen L'spur m. Zerl
oder Brandgranatpatronen
1 Panzersprenggranatpatrone o. Zerl
oder Panzerbrandgranatpatrone (Phospor) o. Zerl.
Here the Minengeschoß appears for the first time. A version of the 20mm M-Geschoß with tracer did not exist, so tracer was used on HE/I (Brandsprenggranatpatrone) or pure incendiary (Brandgranatpatrone) rounds. The latter was apparently a new development in 1944, intended to replace the less effective HE/I. The fifth round was a semi-AP projectile, explosive or incendiary. Apparently the main reason this was used instead of a solid AP round was that a solid projectile would have been too heavy.
It was recommended that more AP or semi-AP ammunition would be loaded when the probable targets were well-armoured attack aircraft such as the Il-2. On the other hand, against the four-engined bombers of the RAF and USAAF the high explosive types were more effective.
30 mm low-velocity (MK 108)
Minengeschoß 108 El o. Zerl.
Only the Minengeschoß was fired by the MK 108, also in versions with day or night tracer. The ammunition was not interchangeable with that of the much more powerful MK 101 and MK 103, hence the addition 108. The letters El probably indicate the presence of Elektron, an incendiary compound, in the projectiles. Surprisingly, self-destruction fuses were not used, although German fighters were operating over the home country at this time in the war. Probably it was felt that this reduced the effective range too much.
30 mm high-velocity (MK 101, MK 103)
1 Sprenggranatpatrone L'Spur o. Zerl
1 Minengeschoß L'Spur o. Zerl
1 Panzersprenggranatpatrone L'Spur o. Zerl
oder Panzerbrandsprenggranatpatrone L'Spur o. Zerl
The MK 103 was a high-velocity weapon with a much better armour penetration than the MK 108. Hence the addition of the older type of HE round and semi-AP ammunition to the mix. The exception were the nightfighters, which used only the Minengeschoß with a glowing trace (Gl'spur).