AP use confusion

[chris h]

I'm confused. Why will the top tank only fire HE at an armoured target, while the bottom one fires AP at the same target. Before anyone says it's out or might be out of ammo, it's not.

[scorpio_rocks]

Because they will fire whichever ammo has the best chance of penetration.

Remember AP ammo performance(penetration) "drops off" over range whilst HE doesn't.

the 57mm with 2 HE and 3 AP pen values will, at all but short range, be better using HE - so thats what it fires. The 37mm with 1:4 will be better with AP at all but extreme range so it fires AP.

To see this easily in a tabular form run the utility "WW2_APCalc2" choose the appropriate weapons and see for yourself at what ranges the different guns will use different ammo.

[chris h]

I experimented with range, the last test was at 1 hex range.

[scorpio_rocks]

Using the utility "WW2_APCalc2" we find that:

the 57mm Type 90 #204 at 50m "Best" AP is 4 the same as the HE value - it's liable to use either...

the 37mm L36 Type 94 #13 has much better stats using AP out till around 450m.

The weapons seem to be working as expected to me - have a play with the utilities provided with the game.

[chris h]

Originally Posted by scorpio_rocks

Using the utility "WW2_APCalc2" we find that:

the 57mm Type 90 #204 at 50m "Best" AP is 4 the same as the HE value - it's liable to use either...

the 37mm L36 Type 94 #13 has much better stats using AP out till around 450m.

The weapons seem to be working as expected to me - have a play with the utilities provided with the game.

I did use the utility and it is as you said. Note I did not know this utility existed until now.

I think this is an instance where the only time AP will be fired is when the tank runs out of HE. Seems AP for this gun is pointless. Having said that I've never tried it in the same hex.

[Dion]

I think AP ammunition is useless on a lot weapons too. It seems to me that weapons will use AP ammunition until the weapon runs out of HE ammunition, not range dependent as believed. I don't want to get my sh!t blown up in the process of closing range to find out, and I don't pay much attention to the attack descriptions on the bottom lower left of the screen, so how do I know if APCalc and the game are on the same page?

[scorpio_rocks]

APCalc uses the same code from the game so of course they are "on the same page"

Don wrote:

Originally Posted by DRG

APCalc uses the games code to show penetration values

HERE

There is a discussion of how APCalc works HERE

[jivemi]

Basically AP and APCR (aka APDS) depend on velocity so their penetration value decreases with range, while HE and HEAT depend on explosives in the warhead so penetration is the same at all ranges. AP Calc tells you what you can expect at various ranges with different guns using AP or APCR; you may notice that penetration often declines drastically as range increases.

[Mobhack]

Some of these early close support tanks do have this problem. Effectively they probably really only should be equipped with HE for game purposes. But the original unit in the original SP game likely had both AP and HE and this got carried forwards with inertia.

The game scores the likelihood of doing damage for each ammo type in its decision to fire. So if there is both HE and AP, and the AP is rather puny then AP is either only chosen at point blank ranges, or never or at least until any HE is expended.

The game uses the average AP rating (as found in APCalc) and not the "best" rating. APCalc rolls 1000 rounds for each range "bucket" and the nest value is the one that came out highest of those 1000 runs through the code - it says nothing about whether 1 or 50+ achieved that "golden BB" value.

That could be the case for little 37mm/47mm/57mm HE chuckers, some HMG with AP where the same applies and so on. Usually inter-war or ex WW1 type weapons of marginal utility in the first place, and usually something primarily there to bother infantry with. The short French guns, for example. Those have "APCR" ammo with theoretically over-penetrating point-blank range but a really short max range so they actually produce a useful AP effect, very near the muzzle. WE did that in the early DOS game - perhaps even the original SP2WW2 hack - since it was a known issue with SSI's implementation of the little FT-17 type tanks popguns.

If the AP value at a particular range is equal then the game will always use HE - because the HE shell goes bang in the target or miss hex, which can cause suppression or even damage to units other than the target. AP rounds that miss aren't effective.

There will always be some sort of little oddities like this, and if we get them pointed out we can fix the OOB (probably by making sure the unit has only useful HE rounds stowed, but maybe by replacing AP with sabot with an extremely short max range as with the little 37mm Puteaux guns).

[jp10]

Not to argue against the many fine points made here, but in the decade after WW1, during the 'Infantry Tank verses Cruiser Tank' debates, the AP function of the gun was more for an anti-material role (especially bunkers) than shooting other tanks. Some designs had a small bursting charge to explode if the round failed to penetrate.
My point being, with these early small bore or infantry support role tanks, maybe the AP function should be considered for short range shots at fortifications and light vehicles, not tank battles.
I don't suppose the ability to 'turn off' selected weapon systems on a unit could be tweaked to allow an ammo type to be not used, allowing a player to select a particular ammo for whatever reasons they foresee?