262 and ju-88 ( and outher sI guess) had this gun
HUGE
The BK-5 was an adaptation of a tank gun and was intended primarily for use against Allied heavy bombers. Its magazine held 22 rounds and the gun had a rate of fire of 45 rounds per minute. BK-5 cannon were installed in some Me 410 twin-engine interceptors and experimentally in the Me 262 fighter, but the war ended before testing with the latter aircraft could be completed. Only about 300 of the guns were produced and combat usage was limited. When Reich Marshal Hermann Goering was captured and questioned on May 10, 1945, he mentioned the BK-5 experiments translated as follows:
"You might find around Germany some jet airplanes equipped with anti-tank guns. Don't blame me for such monstrostities. This was done on the explicit orders of the Fuehrer. Hitler knew nothing about the air. He may have known about the Army or Navy, but absolutely nothing about the air. He even considered the Me-262 to be a bomber and he insisted it should be called a bomber."
SPECIFICATIONS
Weight: 135 lbs.
Muzzle velocity: 1,600 ft./sec.
Gun length overall: 45 in.
Barrel length: 23 in.
Maximum rate of fire: 45 rounds/min.
