WW2 German, Soviet, Allied militaria, uniforms, awards, weapons

I bought a very nice 8,8 cm FlaK cartridge case today and I would like to know what some of the markings indicate. The markings on the base of the cartridge case are the following: 13 P WaA4

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum, armbinden set

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

Tag mlb original, WW2 German, Soviet, Allied militaria, uniforms, awards, weapons

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum

WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum