There’s surprisingly little discussion on how unrealistic this mechanic is for how much more frustrating it makes an already terrible part of the game, that being flying bombers in air battles. If bombs were set to explode on being hit in ground RB, ok, fine. Still not realistic, but slightly better considering we’re assuming the bombers are near the target and the fuses are in. However, with the amount of safety measures most nations have used since WWII to prevent premature detonation (fuses being inserted near battle, “safety pins” that only release upon drop, clockwork fuses that require a certain distance fallen to work), it’s really dumb to have one 20mm round set off a bomb that should be inert until it’s a good 300 feet below the plane.
I think you’re thinking about it wrong, all those safety measures are for the bombs fuse itself. The explosive filler is still going to be just as reactive regardless if the bombs fuse is active or not. The rounds hitting the bombs, penetrating the shell and hitting the explosive filler will make those rounds act like the bombs fuse. The rounds aren’t activating the bombs own fuse, they are themselves acting like the fuse.
How likely it then is for that bomb to explode depends of what type of filler is used.
how dose an AP round ignite and accelerate the burning speed of a high explosive to the point of detonation? And how dose a HE round pen the bomb casing?
Yes it’s possible to detonate a bomb, it’s no where near as easy as it is currently in WT. Nitro-glycerine, famous for it’s ease of detonation and instability can only be easily detonated by impact when there is a reasonably thick layer of it on iron or steel and being struck by iron or steel, it’s possible, but difficult to detonate if one of either the surface it’s on or the striking surface is a slightly softer material like brass. if one of those surfaces is lead, like in a regular (ball) bullet, it is actually very difficult to detonate via impact.
HE rounds still have a fuze delay and can even pen up to 10mm for a 20mm shell (at close range)
Most AP rounds are also incendiary
Which given the shape and thickness of a bomb casing would require an exceptionally lucky shot, even if they didn’t fuse when penetrating the aircraft itself.
irrelevant, it’s perfectly safe to light C-4 or gelignite and cook dinner on it, HE has to be heated for an extended period before it reaches "cook of temperature
Kinetic energy.
This is an exaggerated example with nitroglycerine but you get the idea:
The same way a HE round damages a tank. Either by shrapnel penetrating thinner areas or by creating shockwaves and inner casing spalling.
That point I’ll likely agree to, i don’t have enough knowledge to say how easy it is IRL for any of the existing in game filler variants to explode from outside force.
I don’t think you understand how incendiary rounds work
GP bombs have relatively thin casings, far less than 10mm on their sides