Originally posted by GODO
Tony, I would agree about the straight ray weapon as long as you can aim that accurately. So, IMO, the german aproach was far better with the exception of P38. Do you have stable guns with not so flat trajectory and not so high firing rate? No problem as far as you can use an accurately calibrated and marked gunsight you will be able to score accurate hits easily. Do you have flat trajectory high ROF guns but with high dispersion? You will be lucky scoring a single hit, at least at the spot were you were aiming.
In WW2 it was really important to be able to score accurate hits with the very first burst, most kills were achieved bouncing unaware planes, and you dont want to spray, alert the enemy with few scattered pings and risk a real fight.
I've seen lots of 109 guncam films were the 109 pilot aproach, aim, fire a pair of accurate shots, and then smoke, fire and bye bye spit or hurricane engine. if the gun, due the mountings, become a treacherous tool, ballistics will become secondary.
I agree that centrally-mounted guns were superior (so did many RAF officers) but that was because they avoided the harmonisation problem of wing guns, not because they had less dispersion. Or to put it another way, their dispersion was a gradual spread from the centre, not a constantly-varying 'figure of eight'.
Some dispersion is a Good Thing because it will increase the hit probability, provided that:
1. The shot pattern of a typical burst of fire is still dense enough to guarantee hits against anything caught 'in the cone' at normal combat ranges;
2. Each hit is powerful enough to be effective - i.e. from a cannon, not an MG.
The first gunsight which gave a reasonable chance of scoring hits in deflection shooting was the gyro sight which didn't enter service until 1944. Until then - and still to some extent after then - a high muzzle velocity was a great aid in scoring hits in such circumstances, and even then only the very best shooters could do it.
Of the various sources of inaccuracy to affect WW2 aircraft guns, by far the most significant (leaving aside pilot skill) was the aircraft itself - it vibrated, shook, skidded across the sky and was generally very difficult to keep aimed at the target for more than a second or so. That's partly why most experienced pilots liked to get in real close before opening fire - all sources of error were minimised then.
Rather OT but - Hurricanes and Spitfires could have carried four 20mm MG-FF cannon in the BoB instead of eight .303s, for much the same weight. They could have been much more effective as a result - discuss!
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