30951- ORIGINAL WW2 WWII GERMAN FLAK 30 OR FLAK 38 ANTI-AIRCRAFT "AA" GUN 20MM CARTRIDGE FOR TESTING HEADSPACE MADE OF SOLID STEEL WITH WAFFENAMTS. "WaA109" (Army Weapon Dept "WaA" acceptance stamp) along with "H40" and looks like engineering company logo in circle. This WaA109 waffenamt is Polte AG in Sachsen-Anhalt. It's a solid steel to it's core headspace "Go-gauge" or "No Go gauge" for German Flak 30 or Flak 38 Anti aircraft (AA) 20mm guns. Came in collection of ID'd Stuart Tank driver from the 759th Light Tankers who fought on through the Bulge. NOT an actual loaded cartridge, just a solid steel billet turned by lathe into perfectly sized blank of cartridge for testing internal dimensions of AA gun chambers. Due to high temps of AA barrels attained during high rate of fire the barrels would wear out and/or lose accuracy so the "head-space" had to be checked very often.