US Army Air Force Fighter Gunnery, 1st Edition, Training Manual, June 1944 A-35 Vengeance and our educated guess is

and our educated guess is that this is the altitude of the threat and its air speed relative to the interceptor

and therefore cannot claim its accuracy

as the aircraft's guns have been fired

and functions as it should

Here is an original WWII-era Recognition Poster for the British Royal Air Force Avro Lancaster Heavy Bomber as published by the US Navy Dec 1942

US Army Air Force Fighter Gunnery, 1st Edition, Training Manual, June 1944 A-35 Vengeance and our educated guess isThis is an original Fighter Gunnery Training Manual as used in aerial fighter combat training of pilots of the US Army Air Force during WWII. Its 115 pages cover all that is necessary to know by fighter pilots for air to air combat. It is in good condition for its age. The pages are intact. The cover has become detached from its staples, but it is otherwise reasonable condition. Measures 8. 5 x 11 in and about 1 2 in thick.