trajectory and penetration

[coe]

There's been alot of talk about pentration

at various ranges, etc. etc.

Would it be safe to assume that trajectory

is factored in here.

E.g. for a slow velocity projectile, the

course is more eliptical I assume. Therefore

the impact might have less deflection than

a shot trajectory that is flat.

I can imagine for example if armour is

sloped 45 degrees and an airplane makes

a strafing run at 45 degrees to the ground

it's cannon shot will be 0 deflection (could

this be a reason that lets say a mortar shot dropping directly down over head has a good chance of nocking out a tank (factoring of course that the overhead armor is perhaps thinner)....

[lcm1947]

I don't believe that a slower shell would penetrate better then a faster one even if your example seems correct - as far as it goes. The faster shell would have more energy and I believe would have a better chance of causing damage even on sloped armeor. Example; The Panther's 75mm was so much more effective than say the Sherman's 75mm's due to it's greater velocity therefore greater penetration. I would be anxious to see what one of the more knowledgeable guys would have to say on this subject so hopefully someone will jumb in.

[Andrew H.]

IIRC, CM doesn't model the specific trajectories of shells that hit; I think it would be a big processor hit.

It's also more complicated, but less important, than it might seem. On the complicated side, it's not just a matter of slow projectiles vs. fast projectiles; even assuming the same projectile, its angle of impact will vary depending on the range it's fired at. That is, a shell fired from a German 75/L48 will have a "straighter" impact at 300 meters than it will at 1500m.

The reason this isn't important, though, is because CMs penetration figures correspond with real world figures, and the real world figures already include correction for deflection. So if CM and the real world show an armor penetration of a given gun of at a given range, this result is already going to include whatever effect deflection has. If you fire a shell 1000 meters, the resulting penetration reflects whatever change in deflection occurred as the shell travelled to the target.

I think that CM does model deflection based on different unit elevations -- so a gun firing from a higher elevation on armor sloped at 60 degrees would penetrate as if the armor were sloped less than 60 degrees because, relative to the shell's impact, it is.

Indirect fire weapons, such as artillery and mortars aren't effective against tanks because of deflection; they are effective because their angle of attack permits them to hit a completely different part of the tank. I don't think that any direct fire weapon fired so slowly that it could effectively attack a tanks top armor directly.

[Stixx]

Muzzle velocity is not the only the only factor that gives you penetration.

The weight of the projectile is very important as is the sectional density of the projectile.

Barrel rifling and rate of twist are important factors to stabilise the projectile in flight. If a projectile isn't stabilised before it leaves the barrel it may start rotating inside it's own axis. It may at worst even start "Keyholing". Any of these factors will greatly reduce the penetration of a projectile.

[Dschugaschwili]

The trajectory of a shell is not figured into the penetration calculation. A quick search (knowing that I've asked a similar question before ) finds this answer from Charles why not.

Edit:

Not to confuse anyone, as far as I know the angle of impact caused by height differences between attacker and target (extreme example: a PIAT firing at a vehicle on the road from the top floor of a building standing next to the road) is included in the calculations, just the trajectory of the projectile (the change of direction during flight) isn't.

Dschugaschwili

[ 07-30-2001: Message edited by: Dschugaschwili ]