
If we cannot get a single 5" gun for field defense, how about the German 88mm Flak 36. Definately a well used gun throughout the war, and very common. Would be effective aginst bombers as well as fighters. It would definately force bombers up to a higher altitude, and stop the unrealistic low level bomber runs on VH bases.
Our bases just need better manned ack to deal with aircraft as well as gv's.