The primary anti-bomber weapon of the Luftwaffe for much of the war was the 20 mm MG 151/20 autocannon, which was compact enough to be mounted in an internal wing bay mounting in the Focke-Wulf Fw 190 (up to 4 cannon, or 6 with optional twin-gun underwing pods) and also fitted on the centerline of Bf 109G fighters, firing through the propeller spinner as a Motorkanone.
This could be supplemented by an additional pair of cannon in drag-inducing underwing gun pods, but it was found that it took an average of twenty 20 mm hits to shoot down a typical four-engined Allied bomber.
21, or Bordrakete BR 21) rockets fitted to Messerschmitt Bf 109 and Bf 110, and Focke-Wulf Fw 190 fighters, used to break up the USAAF combat box bomber formations, had launch tubes that were not only drag-producing, due to their exposed five-strut under-wing mounting, but also from the fact that the launch tubes needed to be aimed upwards at some 15° from level flight, to counter the BR 21 rocket projectile's considerable ballistic drop after firing.
A battery typically consisted of two groups of 12 rockets and when all 24 were salvoed in an attack, they would fill an area about 15 by 30 m at 1000 m, a density that made it almost certain that the target would be hit.
The R4Ms were usually fired in four salvos of six missiles at intervals of 70 milliseconds from a range of 600 m, and would supersonically streak towards their target at a sixty percent higher velocity than the Wfr.
The Panzerblitz III, mounting a gigantic 210 mm hollow charge warhead (the same calibre as the BR 21), can be seen as the ultimate development of the basic Orkan rocket.
[6] The Luftwaffe found the R4M missiles to have a similar trajectory to the 30 mm MK 108 cannon's rounds in flight, so the standard Revi 16B gunsight could be utilized.