About WW2 fighter aircraft firing power

[Rob Philips]

Thanks, Juha. I agree that a flatter trajectory decreases the effects of errors, and therefore increases the chance of a hit. I did not agree with the quantification of that statement, in that a 50% higher Vo would give a 5 times higher probability of a hit. That would depend upon a definition of "hit probability", and we do not yet have a good one.

About reverting to the experts: if you could point me to a work on the subject, I'd be interested. We are not talking about civil explosive demolition here, where charges can be calculated to do a certain job under known conditions. In military explosive manuals, you'll find much less theory, and much more empirical data, based on substances and applications as they become available. In military applications, the bigger blast is usually seen as the better one. In civil explosive demolition the opposite is the way to go.

Ammo parameters in our case are given. Energies can be calculated, based on these parameters. The explosive can be seen as a propellant, that projects the fragmented shell bits initially (Vo of explosion) with the speed of the explosion. Therefore, I felt safe to use the energy formula that is used for non-explosive projectiles: E = 0,5xWeightxVsquare. I'm not claiming absolute accuracy here, I offered a comparison of the energy delivered at the target of a solid and an explosive round with the parameters as stated. This data is not found in the ammo manuals, and that's the reason to give it a try. If there is an error in my reasoning, I would like to know which. In any case, hit probability is not effected by the presence or absense of explosives in a projectile, so it really is a sideline here. Hit effectiveness however is greatly effected by the use of explosive rounds.

To Peter: mixing calibers in aircraft armament is a way to achieve compromises, and surely this way introduces new issues resulting from differences in exterior ballistics. That the matter is highly complicated is fully understood. I'm inclined to decide whether it is too complicated only after having given it a try.

To Harri: I understand the point made, and appreciate the effort to come to a quantification of "hit probability". I was not convinced by the result of that effort. The fact that the Germans evolved to low Vo large caliber aircraft armament most likely has to do with bombers being their main targets, as you said, but there may be no direct connection with the achievement of hits here, and more with delivering of the energy levels that could destroy a bomber. That meant shooting with the highest amounts of High Explosive as technology allowed at the time. Not because the bombers were slow, but because more energy on target was needed to bring them down.

Regards,

Rob