Gun Convergance?

[Blackdog_kt]

Much depends on the characteristics of your aircraft as a whole and its proper employment as a complete weapons system.
I haven't been online in months, but when i used to i managed to dig up a manual for the FW190 that was written specifically for the way it flies in IL2.

Some very useful stuff in that one, but when i saw the proposed convergence ranges i jumped in surprise. Nevertheless, i tried it out and to my continued surprise it was awesome. Get ready for it....700 meters

The reasoning was that the 190s have plenty of ammo for long range deflection shots and are slower than P47s and P51s up high so you need to shoot from further out, but you can also outrun other planes on the deck which means you will shoot from close range, in which case you use just the two inner guns (they are mounted very close to the centerline, so they are not affected much by convergence).
However, the vertical component of this convergence setting is what impressed me the most, as it made the Mg151 rounds travel in an almost perfectly straight line like lasers. Ok, they still arc up and down, but i'm not a virtual ace by any means and i still managed to get some 500m deflection shots that did considerable damage.

For example, in one occasion i was hunting a tempest on the deck and he was outrunning me. He was the red teams last available fighter, if i killed him we would win the map. I started giving him some short bursts here and there while requesting cover from the rest of the blue team in my area (there were a couple of hostiles close by but they were kept occupied), watching where my tracers passed in relation to his airframe and adjusting my aim. About 4-5 attempts later i scored a couple of hits on his outter wings that slowed him down, got closer and shot him down.

On another occasion, i had a P-38 cut across my nose from 10 to 2 o'clock...at a range of 1000m or so. I saw this big, nice fat silhouette about to move through my gunsights, estimated the distance, remembered i was set up for long range and had lots of ammo, gave it about 3 gunsight's worth of lead and a two second burst. Imagine my astonishment when i saw hits scored all over his upper wings and fuselage and some of his tailplane assembly flying off the rest of the aircraft.

What's nice with this setting is that people never expect you to shoot that far. So, they might be cutting across your nose thinking that they are safe while they are transitioning to an advantageous situation, only to be met with a hail of 20mm.

The difficult part is two-fold. First of all, it's no small feat to be able to estimate the proper lead at such ranges. Second, when you are close you need to learn to shoot in a totally different manner. The vertical displacement of the guns is so much to enable them to reach 700m that you are not only shooting wide, you are also shooting high. This means that the proper aiming point is not the gunsight's center anymore, you need to have the target at the upper half of the gunsight and push your nose down a bit. Plus, the outer two guns are pretty much useless closer than 350-400m as they will always shoot wide.

However, there is a way to turn this into an advantage as well. With cannons you don't need as much concentration of fire as with maghine guns, so you can use the spread to ensure a higher probability of a hit at the expense of concentration. Even when being a mere 200m from the target with a long range convergence, you can swing that brilliantly responsive rudder left and right a bit and make sure your outter guns have some use, raking the guy from wingtip to wingtip.

All in all, i don't use that setting anymore but it opened my eyes to what a longer convergence can do (not to mention it helps a lot when attacking bombers). Nowadays i fly with anything between 325 and 500 meters in 25m increments, i usually opt for 375m when i'm going to be against faster enemies and 325m when i know i can outrun the opposition. It's still good for longer ranges, but it also makes it easier to score hits when up close.

[swiss]

I really hope we get ballistic tables for SoW.

Also, I would love to set convergence and elevation separately.

[klem]

Originally Posted by swiss

............
Also, I would love to set convergence and elevation separately.

Why is that swiss? in IL-2 you can set different convergences for m/gs and cannons and you need to know that set to 200m, or even 700m, the 'elevation' convergence will co-incide with the 'lateral' convergence or you will have your rounds converging laterally at the set range but too high or too low if 'elevation' wasn't set to the same figure.

[FG28_Kodiak]

It would then be historic correct, german fighter have different values for the harmonization with the sightline and crossover.

For example the Convergence Settings for a FW-190A8

[swiss]

Originally Posted by klem

Why is that swiss? in IL-2 you can set different convergences for m/gs and cannons and you need to know that set to 200m, or even 700m, the 'elevation' convergence will co-incide with the 'lateral' convergence or you will have your rounds converging laterally at the set range but too high or too low if 'elevation' wasn't set to the same figure.

See Kodiak's post.

For the 190 f-.i., I would set the fuselage MG parallel, elevation 150.
Different settings for the wing cannons, if possible each pair their own.

[klem]

Originally Posted by swiss

See Kodiak's post.

For the 190 f-.i., I would set the fuselage MG parallel, elevation 150.
Different settings for the wing cannons, if possible each pair their own.

Swiss, I don't know if I have misunderstood you but Kodiak's post shows the m/g guns harmonised at 400m and the cannons harmonised at 550m. You can do that in IL-2. In each case on Kodiaks charts the elevation/trajectory is also harmonised to 400m and 550m respectively.

At the m/g convergence point (400m) the cannon rounds are about 77cm higher and about 30cm to each side but they converge further on at 550m.

You can harmonise the m/gs at 150m but in that case it would be so close that they would converge on the rise and not on the fall. The would probably fall again down through the sight line at between 300-400m but of course they would be separated laterally by, I would estimate, around 1m.

[swiss]

[QUOTE=klem;198385]Swiss, I don't know if I have misunderstood you but Kodiak's post shows the m/g guns harmonised at 400m and the cannons harmonised at 550m. You can do that in IL-2. In each case on Kodiaks charts the elevation/trajectory is also harmonised to 400m and 550m respectively.[quote]

Kodiak: reason n°1
Swiss: another reason, call it n°2

I have the manuals myself, still - that is my bird, and if I'm able to, my fuselage MGs won't intersect at all, laterally.
Sure I could set a high distance, but then I'm stuck with bullet drop...

Thefore:

You can do that in IL-2

isn't true.

At the m/g convergence point (400m) the cannon rounds are about 77cm higher and about 30cm to each side but they converge further on at 550m.

You can harmonise the m/gs at 150m but in that case it would be so close that they would converge on the rise and not on the fall. The would probably fall again down through the sight line at between 300-400m but of course they would be separated laterally by, I would estimate, around 1m.

Where did you get the numbers from? Kodiaks table or an educated guess?
Are there ballistic tables for Il2?

[klem]

Originally Posted by swiss

............. if I'm able to, my fuselage MGs won't intersect at all, laterally.............
Where did you get the numbers from? Kodiaks table or an educated guess?
Are there ballistic tables for Il2?

Aaahh! you want some separation, laterally, at 'convergence' range. Ok, well that's up to you. Most of us are trying to get maximum, or 'point', concentration at convergence for maximum damage. However on fuselage guns we sometimes set long range like 600m-800m for longer range hitting (which is more achievable with fuselage guns and useful for ground attack) and still good for shorter range air to air with a lower aim. You can't separate elevation from separation in IL-2 convergence setting.

I got the numbers from Kodiak's chart as he put that up as an example and a reference. If they are accurate for that aircraft, and they look like it, the numbers would only apply in that instance but the example is generally relevant to all.

I don't think there are ballsitics tables for IL-2 but there are masses of ballistics data out there on the web. I made a spreadsheet of them from a few good sources.