It seems to me that the Rate of Fire of this gun went up. I don't usually fly 109's but unless my memory fails me I remember the rate of fire as being lower on this gun than it is right now. Is this correct? If so why was the ROF changed upward? Seems high to me for such a large caliber cannon.

SB

Are you kidding? I can achieve better RoF throwing potatoes by hand...
Not to mention muzzle velocity ugh..

Right I know the muzzle velocity is low -- as it should be -- but I'm not kidding. Seems higher than it used to be. I read somewhere, maybe it was here, that it had indeed been increased due to complaining. Maybe I'm mistaken, but this gun can really toss out shells now, or so it seems to me.

SB

The MK108 rate of fire is pretty good actually, historically up to 650 rpm. The MG151/20 is 750 so is not that much of a difference.

This "seems to me" stuff means... nothing. You can measure the rof and even the projectile speed in game, it's not that hard, and come up with some hard numbers. The ballistics of the MK108 seem ok to me...

No doubt this is your ride (MK 108 equipped of course) of choice

if the mk108 shoots 650 rpm, just fly a late 109 that has 65 rounds and pull the trigger and see how long it takes to empty

it should take 6 seconds

The MK 108 had the highest rate of fire of any large calibre aircraft gun in WWII. Tony Williams says 600-650 rpm for the MK 108, while other guns range from 80 to 550 rpm.

The MK 108's weak point was low muzzle velocity, which was the third lowest of any large calibre gun. The result was a short range weapon with a very heavy punch, especially for its weight.

in the original IL2 , till some updtaes later, the MK108 had indeed a lower ROF - but thats long ago....................

From which version to which version? I'm not clear on that.

It may have been pre 4.0. But as Frankyboy points out the ROF was lower than it is now. So it was not my imagination....good....the mind is still here. Anyway, I don't fly the 109 with 30mm very often. Great gun provided you can get up close and your opponent is not doing acrobatics.

SB

Ahhh back that far. Yeah I think there was a tweak to the ROF after someone dug up some better data. Thing is that they start off modeling something one way and then a whole bunch of people get in a frenzy and the ultimate benefit is that long lost documents that may once have existed only in a couple of places are found and tweaks are made if the data is good. Actually this flight simming hobby has probably helped gather allot of knowledge that was previously obscured for a very long time.

Salute

The rate of fire of the Mk108 is of the very best variation.

The real problem with this weapon is that bullet drop due to the very low velocity does not seem to be modelled.

This was a bomber killer weapon, completely unsuited to Fighter vs Fighter action.

Yet in the game, there is no real problem in firing the weapon from almost any horizon, including wings vertical. The bullet drop for anything off wings horizontal and level at convergence should be horrendous, but does not seem to be the case.

As usual and as for many of your post about (against?) the Me109,this is quite wrong Buzzaw...

Its 650 rpm ROF is comparable to a simple 20mm allied canon and at a short range it could blow out any *BIG* target like P51D,P47D and TempestMkV with a *single hit*.This wasn't a bomber-killer weapon,this was a *versatile* weapon.

BTW,at a late stage of the war,some 30mm shells did even see their self destruction system disabled,to increase the effective range of the gun.This doesn't seem to be modelled ingame,no complain about this Buzzaw,uh?

Other points:
The centerline position of that gun on Me109 permitts some interesting advantages:
-The gun recoil effect was partially reduced,thanks to the fuselage structure which is better suited for firing such a heavy armament (when comparing with Fw190-A with 2xMK108 in the wings)
-The aiming was also favorised by this kind of centerline placing,especially at short range.

IMHO,the Me109 was certainly the best MK108 piston carrier/user.
The Me262 jets were also dreadful monsters that brought all those good characteristics up to 4xMK108,still in the nose...





As far as i know,German army was absolute specialist in very high ROF canons...
Ingame,as already said,all is ok.

Let's do a simple test,

Set your game in "arcade mode",then
Realise a ~1 sec bursts on the ground with a Me109 with MK108,and look how many impacts you see.
Play with the timeset to increase the precision of your measures

Here is what i get,in 4.08m:





From 10 to 12 impacts on ground for each test,for one second burst => 650 rpm.

Same results from many patches...

BTW and IRL,a final improved version of MK108 had been tested and was able to reach 900 rpm (!) in the last stages of the WW-II:

From "Flying Guns, World War II" by Williams & Gustin [Airlife, 2003]"

"Towards the end of the war the MK 108A was achieving 900rpm on test, but this did not see service."

OMG...

Thanks to Peter for the info!

@+

In 4.08, Rof of MK 108 for K4 or Fw190 A8, for example is 660 Rps, and 500 or 525 m/s muzzle velocity, depending of used round.

Regards,

Josse

660 rpm and 500-525 m/s fits roughly with the numbers given by Tony Williams. The fact that they are slightly high compared with his figures should give Luftwhiners pause. :-)

I am puzzled about Busszaw's claim about bullet drop though. I thought the ballistcs in the game were physics-based, i.e. a projectile weight of X and a muzzle velocity of Y should give a trajectory that looks like Z (I assume projectile aerodynamics are not factored in).

Is this correct?

I after 7 years - who really cares anyway LOL

would be nice to see 8 .50s hit like 4 20mms so the 1 burst to kill any enemy cannon would equal out the armed and unarmed feel of the game. no matter what ac who ever bounces first and gets hits is usually the victor.

1 pass kills everytime vs 3-4 passes = so much more difficult. Thats why all the usa jockies fly german

Except me.

I fly Soviet.

Eight 50 Cals does not equal four 20 mms.

As you can see from the charts on Tony Williams's site those combinations are about equal in weight if fire, but that's without the explosive effect of the 20 mm shells. Clearly cannon are more destructive.

(Red line = six 50 Cals. Green line = four Hispanos.)


It's also why everybody switched to guns eventually. With the exception of the USAAF that switch was nearly complete by 1945.

Sorry, have to disagree since you have provided zero factual contradiction.

Let's look at the Mk 108 and compare it with the U.S. .50 calibre

Muzzle velocity 505 metres per second.

Compare that for example with the U.S. .50 calibre, which has a MV of 890 metres per second or nearly twice as fast.

Gravitational acceleration is 9.8 metres per second squared, or 32 ft per second squared.

What that means, is that in the one second after a round leaves the muzzle, it will normally fall approximately 4.88 metres or 16 feet due to gravitational acceleration.

There is no straight line for a fired round, all bullet paths are downward curves.

The Mk 108 round will have dropped approximately 4.88 metres or 16 feet at a point 505 metres distant from the muzzle. The .50 calibre will drop 4.88 metres or 16 feet at a point 890 metres distant from the muzzle.

It's more complicated than that. The round starts with a gravitationally acceleration of zero when it leaves the muzzle. As it moves away, the speed at which it moves downwards increases, so in effect, the further it is away from the muzzle, the faster it is falling downwards, and the further proportionately it has travelled downwards.

From this you can see the big advantages that high velocity weapons have, since most of the time, ranges are around 250 metres. A high velocity round like the .50 calibre will travel 250 metres much faster than the low velocity Mk 108 round, and the bullet drop difference between the two will be proportionately much greater.

WWII engineers compensated for bullet drop in their aircraft weapons by making the aiming point for the guns variable, and allowing ground crews to adjust them to compensate for gravitational acceleration. When we talk 'convergence', the ground crews were not only concerned about getting the bullets to come together into a focused stream, they were also compensating for gravity. The crosshair of the sights are lined up directly on the target, but the guns are aimed slightly upwards to compensate for bullet drop due to gravity.

Problem: In WWII aircraft, since 'convergence' is set up on the ground, at a firing butt, with the aircraft's wings level, compensation for gravitational acceleration of the round only works in actual combat conditions when the plane's wings are also level. When the wings are not level, it actually impairs the ability of the pilot to aim, ESPECIALLY when the weapon being fired is low velocity.

Example. A Mk 108 which has been set up with a convergence of 505 metres, in an aircraft which has its wings level, and which is fired at a target level target 505 metres distant will hit that target if the pilot puts the sight crosshairs on it.

If that same Mk 108, set up with that same convergence, aiming at the same target, at the same distance, now has its wings vertically banked to the right, the bullet will not hit the target, in fact the bullet will miss the target by a measurement of 4.88 metres to the right, and 4.88 metres downwards. That is because the convergence in this case, which has the gun aimed up to hit 4.88 metres higher than the target to compensate for gravity, now throws the round to the right, since the wings are vertically banked right. "Up" becomes right. Additionally, the normal effects of gravitational acceleration are still in effect, so the round accelerates downwards at the normal rate, and thus ends up 4.88 metres below the aiming point.

The Mk 108 was designed to fire at bombers, which are a stable non-maneuvering target, able to be fired at from level flight. In that role, it was quite successful, against hard maneuvering fighters, where the chances of a shot from a wings level position is vertually nil, it should be far less successful.

There are other factors which should weigh in on the Mk 108's effectiveness, among them bullet shape.

For example, for velocity retention, an aerodynamic round is very important, ie. one with a shaped nose. A flat headed nose on a bullet works very poorly. A Mk 108 round has a very large flat nose. (a .50 calibre round has a sharp streamlined nose) In addition, the shape of the rounds tail is important. A 'boat-tailed' round, or one which tapers to the rear, such as the .50 calibre will also retain its velocity much better than a round with a flat tail, such as the Mk 108. The shape of the Mk 108 round meant it would lose velocity very quickly. Which meant that gravitational acceleration would come even more into play. As the velocity of the Mk 108 drops off, it covers less distance, and gravitational acceleration drops the bullet path further downwards.

I don't have the time or patience to do the exact calculations for all these variables, but I suspect that the IL-2 model for gunnery does not take into account many of them. Which is why the Mk 108 is so effective in a fighter vs fighter role.

The U.S. Navy did a detailed study on the effectiveness of the .50 calibre versus the Hispano 20mm. They found that three .50 calibres did equivalent damage to one 20mm.

The question is, in the game, do three .50 cals do the same work as one Hispano 20mm?

I fly both the Spitfire with the twin Hispanos, (I do not fire with the .303's in normal combat, I save them for defensive fire in an emergency if I run out of 20mm's) and also the U.S. aircraft with the triple .50 cals in the wings, and for my money, I would take the twin Hispanos anytime.

I fear you did miss something:
A non-experienced pilot who would use "spray'n pray" tactic can't,indeed,hope a proper result in a fighter against fighter confrontation,but even with a MG151/20,German 109 experienced pilots shot at CLOSE ranges,IE about 100 meters from the targeted enemy fighter.

Concerning the MK108 speed projectile,attendant the shell type,the muzzle velocity were rather 525m/s,which corresponds to about 2000kph.

I wish you can explain to me HOW a fat and large P51/47 could avoid a 109 shooting at barely 100 meters behind with a gun that throws twelve shells per second at about 2000kph each,knowing the fact that *only one hit* will butcher the enemy fighter all around the sky..!

I wonder what plane could be fast and agile enough to avoid such a tragedy in such conditions...




Again,at short range,anything was possible.If it connects,their won't be witness i fear.



I don't find the comparison between cal .50 bullet and MK108 shell very relevant;
Concerning the MK108 shell shape,instead of debating about its aerodynamic and trajectory,i would look at the projectile destructive power...And as a matter of fact,IRL the MK108 HE shells contained 85g explosive,which was simply ENORMOUS.
The purpose of this is clear:Crush anything that could be hit,whatever it is easy or not to do such.
And at a close range with 11/12 shells fired per second,whatever the targeted aircraft is,a sensible fighter pilot who is placed in front should consider this gun as a major threat.

- Some IRL infos about MK108

- Some IRL infos about MK108 bis

Oh and BTW,

- MG151/20 ammo details here with other guns

As for the MK108,Germans made MinenGeschoB shells as well for the MG151/20,with 20g for each 20mm shell.Enormous,again.

Hey,by the way and AFAIK,we don't have MG shell for the MG151/20 ingame...No complain about this Buzzaw?

@+

A lot of the discussion boils down to this IMHO. The game engine is almost a decade old by now, and there are quite understandably a lot of variables that it doesn't take into account. Like you I strongly suspect that projectile aerodynamics is one of them.


This seems to fit with the calculations made by Tony Williams and others. My impression is that it fits fairly well with the game too.


For comparison, a 20 mm Hispano shell contains about 6 grams of explosive. Of course four Hispanos each firing at a rate 15% faster than the MK 108 will still produce quite a bit of HE per second, but clearly the MK 108 is the winner when it comes to HE content. The reason is a clever piece of engineering, with the 30x90RB shell having extra thin walls to make room for more HE.

The MK 108 was not strictly an anti-bomber weapon. The Germans calculated that the ideal bomber destroyer gun was a 40 mm, but mounting a gun that big in a fighter was problematic so they eventually settled on the MK 108 instead. Their calculations showed that it would take four 30 mm hits to destroy a heavy bomber, compared to just one 40 mm hit. The best description of the MK 108 would be "heavy general purpose aircraft gun" or something like that.

I thought about this for quite a while. In my mind the reason why the twin Hispanos seems like more than the .50cal...at least in my mind...is that while its perfectly obvious that I'm hitting with both Hispanos its less obvious if I'm connecting with all 6 .50cals consistently. When I do get a good shot off and I see multiple strikes on the enemy he usually goes down but I'm just not good enough to make a perfect shot with all 6 guns connecting at the same time. Thats just in my mind...as I like the .50cal effect of shredding the target but I also find the Hispano to be overall a more effective weapon.

I have temptation to say yes and... no...

So, parameters are not so numerous, BUT.... if aerodynamics and some parameters like shape are not directly implemented, it is a parameter that is really intereting to simulate a good or bad shape for a shell.... (not sure to be clear, my english is horrible, sorry).

It is the parameter named Kaliber.... it don't represent the exact caliber of the shell, but a value that can be taken in account to calculate ability of a shell to penetrate an armor.... so, you can adjust this value for a given shell to penetrate or not a determinated thickness....

For the MK108, if you reduce this parameter, it will penetrate before exploding, but if you take poor aredynamics and light thin shape, you increase the parameter kaliber and your shell no more penetrate...... a way to take aerodynamics and low speed at impact in account Loss rate of speed is not taken in account, but.... general calculation and perfo ability are a pretty good way to have something coherent, or at least with a certain credibility if not totally accurate.

This game is old, but a bit advanced for weapons..... you can set different types of shell, like Ball, AP, API, HE with or without tracers, life time of bullet...

After that, game use same algo to calculate ballistics, by complex physical calculation (don't all understand, not good enough in maths and physics)....


So, surely one of the strongest feature of the game, due to his age, i think.

Wrong.

After a huge series of complaint threads, Oleg implemented MG shells for all German weapons, and in fact made up the ammo loads for these weapons to predominatly contain MG shells, although those types of loads were not nessesarily the most common. This is one of the reasons that the MG151/20 is now more effective than the Hispano 20mm in the game, even though most experts rated the Hispano as better, in fact one highly respected author rates the Hispano as the best weapon in the war, even when stacked up against the Mk 108. I would suggest you take the time to read the following article and study the tables:

http://www.quarry.nildram.co.uk/WW2guneffect.htm

The whole issue of HE shells is one which is also a weak point in the game.

Airborne HE shells are dependent for much of their effectiveness on the penetration of the target's outer skin. A confined explosion is going to do a lot more damage. A shell which explodes outside the skin of the target is only going to direct some 20% of its force against the target, the remainder will be directed harmlessly into the surrounding air.

From what I see of the game, HE shells automatically penetrate. There are no instances that I have seen of shells bouncing off and exploding outside the aircraft.

In fact, a large percentage of HE shells would not penetrate, especially at longer ranges. This is for two reasons. First, HE shells are lighter than comparable Armour Piercing shells, thus possess less kinetic energy. Most of the time, HE shells have a lower muzzle velocity. The combination of the two means less chance of penetration, since a round travelling at a lower speed and with less kinetic energy will have less chance of penetrating. Second, HE shells have flat noses, as opposed to the shaped noses of the AP shells, thus increasing the likelyhood of the shells bouncing off.

The Germans realized this was a problem with their Mk 108 round, and at the end of the war did a re-design which reduced the overall amount of HE in favour of a heavier round, as well as modifying the shape of the round.

There is also the fact that experts concluded that some 5% of HE shells are 'duds', and do not explode on contact. In the case of the German ammunition, this figure is likely higher, since much of the their ammo was manufactured using slave labour, where sabotage was a very common occurence. Obviously this is not modelled in the game.

The games modelling gives a large advantage to weapons which predominantly fire HE, when that advantage does not nessesarily apply in real life situations.

Your comments about the 'experienced' German pilots only firing at 100 meters is completely irrelevant. You obviously have difficulty in grasping the concept of gravitational drop. Whatever range the target is at, there is less chance of a lower velocity round hitting the target than a high velocity round, especially if the firing aircraft has any kind of bank.

At 100 meters range, gravitational drop for a Mk 108 would be more than TRIPLE the distance of the drop for a .50 cal.

Hummmm, Buzzsaw, Vike is right for MG shells, we have not really MG in game, far of that.... (i know perfectly what i state)

Prob for hispano in the game is (was) Lacking of SAPI...... just ball and HE...

And german API (widly used for 20mm in eastfront) have a really very poor ability to perforate in game (much, much lesser as a shvak, by example)

I think you have not really an idea of what we have in the game..... Oleg said many things and.... reality is not allways same in game

Lol,see Josse's post.




OMG,do you really know how did MK108 HE shells perform????
It seems not:
Their purpose wasn't to penetrate the target at all but to explode externally,using the shell bottom as a duct to orientate a maximum destructive power onto the target skin!

For such a purpose,30mm HE shells noses were very sensitive and then exploded immediately after impact,implying NO bounce possible,or it would be really rare.

Before trolling against Me109 or MK108,have a good read Buzzaw

"An enemy plane had to be approached quite close to enshure hits. However, if an enemy plane was hit, the results were spectecular; one hit of an M-shell destroyed a fighter instantaneously, 3 to 5 hits were sufficient to destroy any heavy bomber"

- Details about cartridges for the 30 mm Mk108 gun




AFAIK,the MK108 has only one drawback: Its low muzzle velocity,which implied that German pilots had to use it at close range.Every drawback like jamming when banking sharply were corrected early during the war,making this gun irrefutably the best multi-purpose anti-aircraft gun of the WW-II,just before the MG151/20 and the russian Berezin B20.



Yes,for a guy who IS only USED TO fire .50 cal...

Now please,take into account the pilots who were using MK108 were GERMAN,who were used to fire with some bigger guns than the .50 cal,like MG131/13,MG151/20,MG-FF/M for years.

BTW,I'm still waiting explanations for how a big target like P51/47 could avoid a MK108 burst at 100 meters from behind...

Maybe by going faster than 2000kph and by doing 11 or 12 evasive maneuvers per second..!

@+

I will trust Oleg sooner than I will trust you. If Oleg says he implemented MG then I believe him.



Actually I think you need to read the site you linked, obviously you haven't or you would have seen this:

To quote:

"Type 2 - 3cm M Geschoß 108 ausführung A mit zerleger (3cm Mineshell 108 type A with self destruct mechanism). A Mineshell filled with 85 grams of penthrite and fuzed with the ZZ1589B (Zerlegezunder / self destruct fuze 1589B, -mechanical-). The shell could also be filled with 85 grams of HA41 (Hexogen Aluminium). Weight of shell : 330ħ 8 grams. Note that the shell has a different type of detonator, the VC70. This duplex detonator had a delay curcuit that delayed the shell for about 10 cm of flightpath, enabeling it to enter the target before exploding inside of it."

The description of the MG shell clearly states that it needed to have a delay on the fuse, so it could explode inside the target to be effective.



You show the weakness of your argument by insisting on repeating this absurd comment.

First of all, it may surprise you to understand that not all allied pilots were polite enough to fly straight and level and allow Germans to approach closely to 100 meters behind, that yes, they actually forced the Germans to take some shots from positions which were not as easy, which included high deflection. In those situations, the Mk-108 is definitely at a huge disadvantage.

Your continued insistance that the Mk-108 was designed as an anti-fighter weapon indicates your lack of understanding of the basics of both weapons and projectiles.

Another quote re. the Mk-108 from the site you link:

"It's disadvantages where: low muzzle velocity (ħ520 m/s), resulting in a very curved projectile trajectory and a short range. An enemy plane had to be approached quite close to enshure hits."

This as you want.
Then,i would think the US 12,7mm are perfectly moddelled ingame,exactly like the MK108.
Oleg said it,then i follow you..!



Hey,did you even look at the photos corresponding to the shells in the bottom of the page i posted?
There are seven types of MG shells described into this page,among them,only two were using the VC70 detonator that permitt such a delay...



Interesting.Where did i say "MK108 as an "anti-fighter weapon"..?

I wait.

I'm still waiting.

I was only talking about *versatility* about this gun.Knowing that only ONE hit would bring a fighter down..!



Good.
Just let me add the rest of this sentence you mysteriously omitt,still from the same site:
"An enemy plane had to be approached quite close to enshure hits. However, if an enemy plane was hit, the results were spectecular; one hit of an M-shell destroyed a fighter instantaneously,"

And what was the favorite method of German expertens when engaging an enemy?
Still No clue?

Close range.

You persist to consider German pilots as awful noobs that would only know .50 cal machineguns,this is quite intriguing and particularily irrelevant.In one word: Absurd.



@+

PWND lol

Buzz you are so predictable

Salute

Its typical of people who don't have much logic in their comments, for them to try to fall back on semantics to bail themselves out. You can call the Mk 108 'Versatile' if you want, that won't make the weapon any better.

Here's what you said in reply to my first post in this thread:



In fact, you are the person who is wrong. My assertion that this weapon was quite severely affected by gravitational accleration due to the low velocity of the round is simple physics. No amount of blathering about 'experten' (who were a tiny proportion of the Luftwaffe) or short range firing positions will change the realities of that. In fact, in 1944 and 1945, when the Mk 108 saw most of its service, the vast majority of the Luftwaffe were "Nachwuchs" ('newgrowth') or poorly trained rookies. Your fantasy world where every Luftwaffe pilot was an expert and all Allied pilots flew straight and level to give the Germans easy closerange shots with their wunder Mk 108 did not exist. The only person who would seem to agree with your fantasies would be Goering, who would throw fits and call his Fighter pilots 'cowards' when they failed to shoot down all their opponents, insisting their weapons were perfect.

Bottom line: A pilot flying an aircraft equipped with a Mk 108 would have definite handicaps in attempting to hit a maneuvering target when compared to a pilot flying an aircraft equipped with a high velocity weapon. The reason, low velocity of the round.

That point is confirmed by both the page you linked and the Anthony Williams website which I linked, and in the quotes I linked in my previous posts.

As far as your assertion that only two of the Mineshells required the time delay fuse, that is wrong as well. In fact there are only 4 combat MG shells listed, (the rest are practice shells) and all four have the VC-70 fuse or an equivalent 'self delay' mechanism in the fuse which equips them. But its clear you didn't bother to read the material.

By the way, such shells would be even more in-effective if they did not penetrate, since they would explode after they had bounced off, not on impact.

I am sure you will respond with more excuses, but they won't change the facts. This is my last post on this subject.

Yes,it's absolutely clear.
As clear as your statement about the losing wing on Me109s you said recently.Remember?
Just Here
And then,some answers...here and there with this video.
Enormous.
Enough said about "who is wrong" and who "plays with words"...



Such kind words...Oh and Goering is now my friend,interesting
For sure,with such an impressive self-control,you surely tell the absolute truth.




...And .50 cal won the war.

BTW,from the "Type 4" MG shell paragraph,the author wrote "self-delay" instead of "self-destruct" => I.E. "Zerleger" is the german name given to the self destrucion mechanism.
If you had read my link carefuly,you'd notice that for the "Type 3 MG shell",we have the VC70 detonator that permitted a delayed explosion, but WITHOUT self destruct mechanism (ohne Zerleger).
But naturally you didn't notice this detail and immediatly accuse me to not read carefuly.



Yes sure,MK108 was known to be a very forgiving gun for its targets!

30 mm guntest on a Spitfire wing on ground.

I wonder why bombers aircrews called it the Pneumatic Hammer...Surely for the poetry of a forgiving gun



Hey but the debate was only beginning! Come back!
Talking about Me109 and German guns is rather interesting,especially with you.
So see you next time in another "Me109 lost its wings and its guns didn't exist" thread!

@+

That's valuable information.

The drop is approximately but reliably calculated thus: y=1/2*g*t*t ; t=x/v . x=100m; v=890m/s; g=9.8m/ss

The bullet drop of a .50 shell is about 6cm, and that of an MK108 about 18cm. However, there are two other factors that have to be taken into account: the size of the fighter aircraft as the target, and the gun barrel's elevation (to let the gun shoot slightly upwards) to compensate for the drop. The second factor makes your argument weak already, as is easily seen; and even the first factor, alone, speaks louder than the "triple distance" arguement - 18cm is a very small length compared with the hight of the target fighter's fusalage, which is nearly 2 metres. What does that mean? A disc 2 metres in diametre in front of a gun with an error of 20cm - nobody will ever miss the target disc if he knows to aim at the centre of the disc.

Some official documents sure won't hurt here:



taken from the weapons manual for a G6/U4

Well, four .50 caliber rounds hitting the same spot as a 40mm shell would cause roughly the same damage - and there in lies the rub. One has to hit at convergence.

However, two .50 caliber rounds that hit, even when greatly dispersed, do infinately more damage than a cannon round that misses!

The USAAC and USN/USMC used .50 caliber machineguns for a much more practical reason than "this damage versus that damage," however. The USA was making a crapload of .50 caliber rounds and machineguns, and it was common training for armorers to maintain and repair them.

One could send huge pallets of .50 cal rounds on ships and not a one would go to waste. What the air corps didn't need, the Infantry and Armor could use, and vice versa. No hold space on ships wasted on odd-caliber rounds - something very important when one was sending them to the other side of the Pacific Ocean.

I remember reading that the 3 gun 109 was very unpopular when it first entered service because the pilots saw it as 1 gun less but when they saw what the central cannon could do together with the increased rate of roll due to less weight in the wings they grew to like it very quickly. The advantages were diluted with the heavier G model though especially with its underwing cannon.

I could easily be wrong but I always understood that with increased action against bombers it was thought that it was better to get in a few heavy rounds as quickly as possible in passing fire rather than sit behind in a vulnerable position spraying smaller rounds.

By the way I thought this was a nice pic of the MK mounting.

PS I realise that the central gun changed through the F and G series....

... wouldn't hurt to do some more teing ingame, Buzz. Still I am absolutely convinced that bullet-drop is modelled in IL2 esp. in case of firing an Mk.108. I can't hit sh*t AFTER lining up in perfect six against level flying bombers. I score three hits throughout 6,5 sec. firing time. They drop, disperse heavily while the few rounds in the sweet spot give neat puffs in Mustang fuselages or cause non-catastrophic cooler-hits soothing you with foresights of three doomed enemy fighters outspeeding you in 5 min. runs easily.
I usually prefer slashing attacks which in case of the Mk108 has your oponent fly through the gap between the shells way too often - due to its low rof. You're never carrying enough ammo to repeat those slashes until you succeed in downing your opponent.

The MK108 is my least favorite large cal. weapon in game bar the 47mm built into the cobras.

Greets,
muffinstomp

Does anyone know why in this graph the sighting line (visierlinie) is not drawn as a horizontal straight line?

I missed your point on the first read... I actually think it is just for clarity. You could swap the graphs but that would be even more confusing, IMO.

Oh I find the slanting sighting line a bit confusing. I've seen a similar weapons trajectory graph in an Fw190-A8 manual. But there the sighting line is horizontal, as is what happens in reality when the fighter's guns are being calibrated on the ground.

The reference point is barrel elevation (Mündungswaagerechte) ie 0° or horizontal

Ah! I see . But only the MK108's barrel is horizontal.

The main culprit missing is effective bore. There's no possible way the developers could have this data individually modeled, let alone have acquired the data for every type. It's pretty easy to learn gunnery when every type has the same airspeed to AoA relationships.

Here's two harmonization charts both for P-47's, same aircraft but worlds apart in how the guns are physically set up. Seriously doubt you'll match the same specs for either in game. The FP, FSL, and Mil Rad angles for this specific aircraft won't match generic game data........

You may have accurate ballistics and ballistics modeling, but that's only half the story.

The two images are quite fascinating .

It's disappointing that such game data as a certain gun's muzzle velocity in IL2 have never been made public.

nodak, your charts look like "pattern harmonization" (you get a stream of bullets covering an area ahead of you at different distances) and "point harmonisation" (all bullets cross their paths ata defined point) which were the two basic choices for fighters back then

the game models the latter one, maybe not perfectly, but it's the "standard modelling" for IL-2