Original U.S. WWII USMC Named 4th Marine Aircraft Wing Uniform - Sergeant David Meckel German Documents & Books rear of the barrel has

rear of the barrel has the correct serif "X" sub inspector's mark above the barrel witness line

Stereographs by Weixler

which is definitely 6 bore/gauge

Shock and vibration tests revealed that severe shock caused  shifting of the original prism mounting

Original U.S. WWII USMC Named 4th Marine Aircraft Wing Uniform - Sergeant David Meckel German Documents & Books rear of the barrel hasOriginal Items: One of a kind set. USMC 4th Marine Air Wing Uniform set named to Sergeant David Meckel who enlisted on 30 Jan 1943 and was released on 30 Nov 1945. The 4th Marine Base Defense Aircraft Wing was commissioned August 22, 1942, at Marine Corps Air Station Ewa (MCAS Ewa), Hawaii. The Wing's three squadrons were located at Midway, Ewa and Samoa with the headquarters at MCAS Ewa. In the fall of 1944, the 4th Marine Base Defense Aircraft Wing