>The guns on a bomber were never really meant for engaging aircraft. They're meant to deter fighters from ever getting near the bomber. Not many pilots are willing to sit directly in the path of machine gun fire, even if it is not very accurate. German anti-aircraft figured this out as well. They switched to shooting mostly tracer rounds. You aren't going to hit anything in the first place, so you might as well just scare the crap out of them.

Never really meant? Some citations there would be nice.

US day bombers that were not protected by fighters often suffered heavy losses against the Luftwaffe. Which is why unescorted daylight bombing was suspended following the 25% casualty raid on Schweinfurt.

>They switched to shooting mostly tracer rounds. ..right. What I've read is that many units stopped using tracers altogether on pure fighters because their different ballistics at long range meant that they were not useful. The gas created when the base of the tracer burned diminished drag. (this has later been adopted for howitzer ammo, base bleed increases range by up to 30%)