The MG 15 was a 7.92 mm machine gun developed by Rheinmetall-Borsig during World War II as a derivative of the company's MG 30 infantry weapon. It was used on almost all Luftwaffe bomber aircraft as flexible-mounted defensive weapon. A machine gun is a fully-automatic firearm that is capable of firing bullets in rapid succession. ... World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrinations, and the use of new, extremely devastating weapons like the atom bomb World War II, also known as the Second World War, was a mid-20th-century conflict that engulfed much of the globe... The Luftwaffe? (German: air force, IPA: [luftvafÉ]) is the commonly used term for the German air force. ...
Starting with 1942 the MG15 was replaced by the Mauser 7.92 mm MG81, MG81z (twin-MG81), MG131 13 mm machine guns or MG 151/20 20 mm cannons. The MG 131 was a 13 mm machine gun developed in 1938 by Rheinmetall-Borsig and produced from 1940 to 1945. ... The MG 151 (MG 151/15) was a 15 mm cannon produced by Waffenfabrik Mauser starting in 1940. ...
Machineguns derive their limited armor-penetrating capability both from the single bullet's penetration ability and from the effect the repeated hits of bullets in quick succession - as is the case with a machinegun - onto the same spot have on thin steel plates.
Development of the german machineguns went towards a general purpose machinegun, therewith abandoning the differentiation hitherto between light machineguns carried around by the assaulting infantry and heavy machineguns that were intended as stationary support weapons.
With the occupation of czechoslovakia in 1939 the germans captured 31,204 machineguns of the types ZB 1926 and ZB 1930, mostly the latter.