.50 cal vs Tiger I tracks = immoblization?

[JasonC]

Well, in CMBB I've seen IL-2s with 2x23mm strafe Panthers and get immobilizations from track hits. Quite frequently. They occasionally get top hit partial penetrations, which can lead to abandonment. The game seems to model AC guns as very accurate and as effective anti-armor weapons, probably far beyond what they actually did.

Incidentally, I am much more skeptical the pilots actually hit the tank at all, than that all the hits had to be ineffective. The evidence of tanks KOed from the air just isn't there. Even when they had 5 inch rockets. Since there is little doubt that a bomb or rocket can hurt a tank but the tanks weren't actually hurt, the inference has to be the planes flat missed.

The kinetic energy added by a diving fighter bomber is considerable (plus 150-200 m/s) and might boost 50 cal penetration beyond the levels seen on the ground. It is a similar velocity difference to that between plain AP and APCR, or between e.g. a US 75L38 and a German 75L48. Top armor is often quite thin, certainly compared to fronts. As for angles, P-47s regularly dive bombed, at angles up to 80 degrees from 10,000 feet. It increased bomb accuracy compared to glide bombing. It would also mean the closing velocity boost might reach the 250-300 m/s range.

What seems to be vastly overmodeled in CM is (1) the pilot acquiring a proper target visually and (2) nearly perfect accuracy delivering the actual shot. In reality, fighters hit things as small as other fighters only by matching speed and bearing. They can hit huge targets like bombers with deflection shots, though head on is about as safe and easier to line up.

Deflection shooting against small fighters, even at lower, 200 mph closing speeds, is very hard and only aces did it regularly with any success. Shooting a tank on the ground out of a dive is as hard as deflection shooting at 300-400 mph. And you have less time for it, since you must pull away sooner to avoid a crash (you can just fly by an air target).

When deflection shooting, moreover, the usual technique is to create a bullet stream that crosses the apparent path of the target. You do not put the full stream into it. It relies on a few hits being sufficient. That is why it was more successful e.g. against light Japanese planes (often with no pilot armor, no self sealing tanks) than in Europe.

When the crossing speed is 150 m/s, a one second burst sprays over that distance. It only contains 50-65 bullets (the 50 cal fires about 8 rounds per second). The spread is 2-D as well, but that means crossing a stream might produce 1 hit per 2-3 m of target size. We are not talking about putting 100 rounds into one tank, but more like 2-5, on a good pass. (That is a "hit"). The expected effect would be about like shooting at the tank with an ATR for a minute.