kwk 38 cannon or machinegun

[chuckfourth]

Hi All
The KwK30 and KwK38 Guns were fitted into the panzer II, sdkfz 222, sdkfz 231, sdkfz 234, sdkfz 250 amongst others. It was obviously a popular and widespread weapon used throughout the war. It was an adaption of a flak cannon able to fire single shots. In version 6 of this game this weapon had its "correct" ammo loadout of 90 HE and 90 AP. However when this weapon was reclasified as an autocannon for v7 its ammunition loadout was drasticly reduced. For example in the case of the current sdkfz 222 to 10 HE and 10 AP the assumption being that the gunner is unable or unwilling to fire single shots. So the vehicle now has 20 bursts rather than the previous 180 shells.
For the 10 HE bursts the gun gets the compensation of a higher HE Kill factor. for the loss of 80 AP rounds it gets AFAIK, no compensation. If the vehicle is facing either a hard or a soft target it is out of ammo for its main gun in two turns, ie as currently modeled it can have a useful battlefield life of 6 minutes, which to me seems a bit short. One of the underlying assumptions for this change is that commanders are in the habit of firing off the entire magazine in one burst ie 10 shells. The reason the germans used this gun in particular was because it was magazine fed, not to increase rate of fire but to relieve the commander from the burdon of reloading allowing him to concentrate on command, in a two man turret and command and gunnery in a one man turret. Firing the large bursts as currently modeled means the Commander is busy continually reloading which ignores the reason for its use in the first place
Some arithmatic, if the weapon fires single aimed HE shells then each should have a HE Kill of 1 (my preference) if it fires a 90 round burst HE kill should be about 90. Currently it fires a 9 shell burst so the HE Kill should be about ten. (actually 12 in game, giving a conversion factor of 1.2). If the commander was a little more sensible then he might fire two five shell bursts giving 18 instead of 10 HE bursts, each burst with a HE Kill 6. Or if he maybe has had some training he is firing three shell bursts giving 30 HE bursts in total, each with a HE Kill of 4.
After some mobhacking and testing I think the weapon if by far most useful with 90 HE rounds each with a HE Kill of 1, not forgetting that you get 6 or so shots per turn. This gives the weapon some battlefield persistence and allows it to zero in on a target without wasting all its ammunition doing so, especially after moving. I justify this with the assumption that it is employed as a main tank gun rather than an oversized machine gun.
So HE is simple to model, bursts of AP are another matter. Again each burst is firing 9 shells if the burst hits is the routine that calculates penetration called 9 times? if not then the AP ability of this weapon is seriously underrated, even if this were so would any tank commander seriously fire 9 round bursts of AP? Surely he would fire one shell at a time until he is on target? just like any other tank gun? and then perhaps, just perhaps fire a burst but most likely single shots would remain most advisable.
For these reasons I think that 90 AP Shells is a much better option than 10 AP bursts and for simplicity and practicality 90 HE at HE Kill of 1 seems sensable also. As far as I can find the weapon recieved 180 rounds no matter what vehicle carried it.
To summerise I believe this magazine fed weapon was chosen to remove the neccessity of a extra crew member, the loader, not to increase ROF. So its employment should be as a single shot main gun, jusifying the ammo loadout of 180 shells.
I would appreciate it if this thread wasnt moved into the OOB area as I think it deserves some general discussion.
Berst Regards Chuck.

[Cameronius]

Chuck,
I agree that using this weapon to fire 9rd bursts is unrealistic. But giving up the auto fire capablity also seems unsuitable. Perhaps a 3rd burst best models to use of this weapon on average. The problem here is that it was used in both auto and single shot firing and it is not possible to model this into 1 weapon slot.

[Smersh]

What about 30 rounds of he, and 90 rounds ap. He fires a 3 round burst, and AP fires single shot?

the weapon stats would have to be adjusted to reflect a 3 round burst over a 9 round one.

[narwan]

Same problem still exists, it won't model the auto fire with AP ammo. For the types of vehicles using this weapon getting on target quickly was fairly important as they were fairly vulnerable themselves. Only single shots would mean that in the span of several minutes they would fire only a maximum of 6 rounds. While in reality a lot more than 6 would likely have been fired. Even if not firing in full auto mode, the weapon still allowed a rapid succession of shots. So giving them 90 AP ammo would lead to game effects that aren't realistic either. For example they'd rarely if ever run out of AP ammo during a game while in reality they could fire off their complete ammo load in a matter of minutes.

The simple way to model that is to model the weapon firing bursts, with an adjustment made for accuracy (compared to what it would be for single fire mode) reflecting that the first few rounds fired are for 'zero-ing' in. That abstraction also takes out the need to call up the hit routine several times. Could well be that the current system does just that.

What I think the question that could be discussed is is not single fire or auto, but how big the bursts should be. In other words how much ammo is carried, how big the HEK and accuracy should be to reflect these bursts to have the resulting game effects be as close to actual use as possible.

Narwan

[cbo]

Talk about flogging an old (but perhaps not quite dead ) horse....

Just to keep others in the loop: Chuck brought this up on the old Yahoo board in January 2005, were it was discussed quite a lot. Some things have actually changed since then, partly accomodating some of the issues that were raised at the time.

Lets look at a bit of data from the German OOB....

The German 2cm tank and armoured car gun is found in several different versions:

Weapon #37 2cm KwK 30 Gun (Class 5)
Weapon #8 2cm KwK 38 Gun (Class 5)
Weapon #58 2cm KwK 35 AC (Class 5)
Weapon #17 2cm KwK 38 AC (Class 19)
Weapon #38 2cm KwK 30 AC (Class 19)

The Class 5 weapons are the basic turret mounted weapon while the Class 19 weapons also have an AA capability, reflecting the special mount found in some German armoured cars. The KwK 30 is the early version, the KwK 38 is a similar, but later design and the KwK 35 is an oddity found only the the Austrian ADGZ armoured car used by the German Army. So all the KwK 30/38 are basically the same type of weapon, that could fired burst or single rounds as the gunner pleased.

Then lets take a look at the vehicles in the OOB that carries these weapons and their ammo load, looking at the number of rounds carried in the game vs the actual ammo load (actual load mostly from Chamberlain & Doyle):

834 - PzKw IIa/b: 36/180
002 - PzKw IIc: 36/180
388 - PzKw IIc: 36/180
460 - PzKw IIc: 36/180
835 - PzKw IIc: 36/180
215 - PzKw IId: 36/180
003 - PzKw IIf: 36/180
836 - PzKw IIf: 36/180
838 - PzKw IIf: 36/180

004 - PzKw II Luchs: 36/330

585 - Maus V2: 100/?

390 - SdKfz 222: 20/180
391 - SdKfz 222: 20/180
844 - SdKfz 222: 20/180
068 - SdKfz 222: 20/180
(Class 19 weapon)

070 - SdKfz 231 (6): 22/200
392 - SdKfz 231 (6): 22/200
833 - SdKfz 231 (6): 22/200

071 - SdKfz 231 (8): 20/180
384 - SdKfz 231 (8): 20/180
590 - SdKfz 231 (8): 20/180
845 - SdKfz 231 (8): 20/180

072 - SdKfz 234/1: 52/480
(Class 19 weapon)

162 - SdKfz 250/9: 22/100
383 - SdKfz 250/9: 22/100
860 - SdKfz 250/9: 22/100
(Class 19 weapon)

950 - Aufklarer 38t: 20/180
951 - Aufklarer 38t: 20/180
(Class 19 weapon)

Some inconsistencies aside, it would seem that in general, one shot in the game terms equals a 5 round burst from a tank like the Panzer II and a 9 round burst from armoured cars.
Exactly how these numbers were reached, I dont know. As has been pointed out several times, they may have been made by different OOB designers for different reasons over time as the game developed and the logic behind the differencies may seem rather fuzzy by now. In any case, these are the actual numbers that we are dealing with.

In the game, the 2cm KwK can only be treated as either an autocannon (firing bursts) or as a single shot weapon. In reality, it could do both and I think we can safely assume that the gunner would choose whatever option he thought appropriate for any given target. There is, however, no way to model this kind of flexibility in the game.

Chuck makes the case for treating it as a single-shot weapon, so allow me to make a few arguments for treating it as an automatic.

- The 10-round magazines were loaded with an equal amount of AP and HE, alternating the rounds. So in many cases (in combat probably most cases), selecting the right ammunition for the job would mean firing two rounds. This suggests that giving the Panzer II 180 single-fire rounds (90 HE, 90 AP) is excessive.
- Combat reports from France in 1940 suggest that since the 2cm gun wasn't very effective in penetrating most French tanks, the preferred method was to fire bursts against them. That would often rattle the crew sufficiently to have them surrender or bail out (but did not result in penetration, apparently).
- Same combat reports speaks of bursts being fired against enemy anti-tank guns.

Point being that bursts were fired against targets requiring AP as well as HE. And both type of targets did in fact recieve a dose of both due to the way the magazines were loaded.

So a single-shot weapon with 180 rounds would be just as wrong or right as a full-auto weapon with only 20 rounds.

It would seem that OOB designers have taken that argument into account in the case of the Panzer II, taking the middle road of giving the tank 36 rounds, representing 5 round bursts.

It would seem to me that the armoured cars armed with the Class 5 weapon should be similar to the tanks, while I guess you could make the case for the Class 19 weapons firing 9 round bursts by virtue of the their AA-capability. Firing against planes, they would likely try to get as many rounds into the air as possible.

Claus B

[narwan]

I didn't mention what I thought a reasonable size of burst would be but I was thinking about 5 rounds. But I didn't realise that the ammo was mixed, which almost halves the effective ammo load (as half the rounds fired at soft targets would be AP and half the rounds fired at hard targets would be HE). If you take that into account and still assume a 5 round burst of rounds of the appropriate type (which means also wasting 5 of the other type making it a burst of 10 rounds total), you more or less end up with the current ammo load for the armored cars.

Alternately, you could assume a 3 round effective burst, meaning 6 rounds would be spend in total which would result in a slightly higher ammo load (15 HE and 15 AP). Problem with that is though that the ammo cases don't come in multiples of 6. But that's an abstraction we could overlook I think.


Narwan

[chuckfourth]

Hi Narwan,
So just let me check, You dont want to change back from burst to single shots because we wont run out of rounds quick enough? So instead the designers should somehow work out what the accuracy should be changed to if we want to factor zeroing in for the number of rounds in a burst (which is probably not possible as it appears zeroing is a function of no of bursts not rounds in a burst) and change the code to call multiple hit routines, when the alternative is to just change the ammo loadouts for the different vehicles back to what they were in v6 of the game?
By the way what happens I wonder if the first round in a burst destroys the target? dont forget were not firing whole magazines just single, albiet fast, aimed shots, then the the rest of our "burst" 8 more rounds is wasted, right? what of the second round in the "burst" is satisfactory? Heres an example of the problem,
For antipersonal work these guns have a coaxial MG so the HE rounds are mostly for soft targets such as trucks AT guns etc, I did a test, Using 222 as our example with HE Kill set to 1 and then to 12, everything else unchanged. Firing at trucks at close range it takes 2 shots to destroy the truck in both cases (HEk of 1 and HEk of 12). So with burst modeling we have to spend 18 HE rounds to do 2 rounds work, No matter what burst size you choose you will "lose" a goodly proportion of your HE and AP rounds because of this effect. So Sdkfz 222 with the "correct" ammo loadout of 90 HE can destroy 45 trucks in a game, but with the current loadout of 10 HE it can destroy 5 trucks only.
Soft vehicle effect is I think a very strong argument for changing the HE loadout back to the actual number of rounds as in v6 of the game. ie increasing the HE Kill doesnt compensate for the change of ammunition from single shots to bursts.
Getting on to target involves a lot of factors other than ROF; range, vision, optics, traverse and elevation speeds all play a part.
A LMG MG42 can also fire off its complete ammo load in a matter of minutes, did it?


Changing back to single shots only downside is that we have to assume the gunners are firing single aimed shots ie have some training.
disadvantages of using bursts are
Because of limitations in how bursts are modeled the majority of rounds now have no effect
For HE shell types the increase of HEK does not compensate for this loss. AP shell types are uncompensated.
Hit routine needs to be called several times for AP burst modeling to be correct but how to handle first round hit?

Regards Chuck.

[narwan]

Don't put words in my mouth. Size of burst, accuracy of weapon and HEK are all related. What I said is that IF one would want to change the burst size you'd have to think of the other two too. Just as the designers have already done for the current version. THAT is all.

Again you seem to miss the point of abstracting real world effects into a workable game system by coming up with an example were real world effects aren't exactly matched by what the game has to offer. Guess what, it doesn't matter which way you go to model this, one will always be able to come with such an example. And not just for this gun. It's inherent of ANY model, game or no game.

This micromanaging is pointless. Take that final question for example "how to handle first round hits". Doesn't matter. Just like it doesn't matter that if an infantry squad fires their rifles and kills a sniper on the first try, ALL riflemen in the squad effectively lose a round of ammo even though the first one to fire could have hit the sniper. It's an abstraction.
If you're so worried about first round hits, just assume that the gunner isn't sure (and often can't even be sure) if the target is really out with the first round so puts a few more rounds in it. Makes sense since he can do that very rapidly with this gun and he's got plenty of ammo. He could wait a few moments to get a clearer picture, with the risk of being treated on for example a handgrenade or not wait and just put a few more in there. Better to be safe than sorry, right? Sounds realistic to me too.

There's no doubt for me that this weapon is far better modelled as a burst fire weapon than as a single shot weapon (so a big no on going back to v6 of the DOS game on this). And as I said earlier, if you assume the burst to contain 5 rounds of the relevant ammo type and assuming that the ammo was stacked alternating between HE and AP you end up with what you have now.


Narwan

[chuckfourth]

Claus said:
Exactly how these numbers were reached, I dont know. As has been pointed out several times, they may have been made by different OOB designers for different reasons over time as the game developed and the logic behind the differencies may seem rather fuzzy by now. In any case, these are the actual numbers that we are dealing with.

As chief apologist for these phantom OOB designers you should know that these changes all came into place after v6 of the DOS version. The logic is that the weapon was now to be treated an anything other than a main gun, whether mounted in either a tank or an armoured car. The weapon is now forced to be used an an oversized machine gun or as an AA gun. The problem is that these secondary roles have been interpreted as its main function and then modelled incredibly poorly, making the weapon virtually useless, ie because it could fire bursts it now has to always fire bursts. This is about as sensible as modeling MG34 as a rifle because it could fire single shots.

Claus said:
- The 10-round magazines were loaded with an equal amount of AP and HE, alternating the rounds.

I would like to see a reference for this statement I would think the magazines would contain either HE or AP. Even if this is true and using sdkfz 222 as an example its ammo loadout should be 45 HE and 45 AP not 10 HE 10 AP. And in any case HE is not totally ineffective aganst Hard targets and AP still puts a hole in a soft target so to model bursts a number somewhere between 90 and 180 would be appropriate. The crew would certainy vary this if they found they were running out of ammunition anyway.

Claus said:
- Combat reports from France in 1940 suggest that since the 2cm gun wasn't very effective in penetrating most French tanks, the preferred method was to fire bursts against them. That would often rattle the crew sufficiently to have them surrender or bail out (but did not result in penetration, apparently).

Would you be able to share these combat reports with us Clause? Firstly when the weapon is mounted in an armoured car which has bumped into french armour the response is to get the hell out of there and report it, not engage in a pitched battle that cant be won, And for the panzer II in a panzer regiment, again best to go round this sort of opposition rather than get shot up, leave the french tanks for the infantry AT or pz III or better. Not forgeting these french tanks were encountered peicemeal.
In any case This is a rare occourance and so doesnt justify modeling bursts, These vehicles are far more likely to meet other similarily thinly armoured reconnaissance vehicles in this case it is more useful to fire single shots.

Claus said:
- Same combat reports speaks of bursts being fired against enemy anti-tank guns.

Still probably more accurate to fire single shots at about one a second than just pump off the entire magazine. This allows enough time for the firer to gauge the effect.

Claus said:
So a single-shot weapon with 180 rounds would be just as wrong or right as a full-auto weapon with only 20 rounds.

No because no one fires 9 round bursts. Also modeling single shots works fine, However modeling bursts is a failure resulting in the weapon taking a massive performance drop.

Claus said:
It would seem to me that the armoured cars armed with the Class 5 weapon should be similar to the tanks, while I guess you could make the case for the Class 19 weapons firing 9 round bursts by virtue of the their AA-capability. Firing against planes, they would likely try to get as many rounds into the air as possible.

Again replacing the weapons primary function with its secondary function resulting in a huge performance loss. How often did these vehicles fire at aircraft ? considering that in the first half of the war germany pretty much had air superiority wherever they were, And the weapon is in reconnaissance vehicles not likely to be targeted anyway. In the second half of the war when enemy air was a problem, the 234/1 appeared, I notice you have convieniently missed out the ammo loadout for 234/1, its 480 rounds. Perhaps by this time of the war the AA capability of the weapon was becoming important enough for bursts to be fired and hence the appropriate larger ammo loadout. ie when these guns did begin to be used regularily as AA they were given the correct ammo loadout to do so. note also the 250 replaced these armoured cars on the eastern front and had the smallest loadout, however germany could still gain local air advntage on this front for attack when these reconnaissance vehicles were busiest.

Claus you have suggested some very limited and highy specific examples where bursts may be appropriate but in the vast majority of cases single shots are more apropriate, thats the real world
In the game forcing bursts results in a seriously underperforming weapon for no gain, disadvantages being:
Only one AP round in each burst actually has an effect.
The number of soft targets that can be destroyed is seriously reduced.
When firing single shots each successive shot is more accurate, with bursts you cannot track on to targets this way and waste vast amounts of Ammo doing so.
Any comment on these 3 points Claus or am I correct in these statements?
Regards Chuck.

[chuckfourth]

Hi Narwan
In the real world yes he has plenty of Ammo in the game world he effectivly has only 10 AP rounds as he has to fire a full burst each time. I am not micromanaging I am pointing out that everytime sdkfz 222 hits a kills a target with its first round it will always then proceed to pump a further 8 rounds inot the target very unrealistic. Please take the time to read and understand my posts as otherwise you are forcing me to repeat what I have already said to help you understand my point. You are very good at saying burst is better but you fail to supply much justification, you think it is more realistic which obviously it isnt and other than that the only contribution you have made is to say that the rate of ammo usage, all AT expended in 6 minutes seems correct again this is obviously wrong.
Best Chuck.