Gun convergence on Bf 109

[lonewulf]

Sorry, none of the above helps me. I'm still not getting it I'm afraid.

vertical convergence == 400 m (Visierschuss)
horizontal convergence == 420 m (Kreuzung)

Ok, as an example, let's use the values listed above. But before that can I just stress that we are only concerned with convergence here, not burn-out and not fusing.

To remove any inconsistencies with the grouping we get from our guns let's assume for the purposes of the test that we have perfect weapons being fired from a perfectly stable gun platform. Ok, so in this case we adjust all of our forward firing weapons to converge at a range of 400m in front of the aircraft in the vertical plane. Now, because we have perfect weapons etc the projectiles should all go through a single (ragged) hole at exactly 400m in front of us. Ok, so far so good. Now we introduce our slightly different horizontal convergence value. In this case that's 420m. Right, so now we appear to have a problem, at least as far as I'm concerned. How can our perfect weapons fired from a perfectly stable gun platform put a single (ragged) hole in two different points in space at the same time? Do our guns converge at 400m or 420m, which is it??

Slipball, you said; "This is a very easy concept to visualize...your friend is a good distance away from you. You want to hit him/her with a snowball, you realize that you need to give a greater angle upwards when thrown, so as to not fall short and to make that hit....drag/gravity!"

Ok, so are you suggesting, if we go back to the sim, that for your projectiles to converge at 400m in front of your aircraft they would have to be fired along a trajectory with a 420m high-point above the line of sight? If you are suggesting that, then I think you're seriously mistaken.

[VO101_Tom]

Originally Posted by vranac

Tom, did you look that track from outside view?
Maybe your plane is shakin a bit because of cannons shoting.
I think plane was fixed somehow when guns was adjusted on target.
If I remember right some picture was shown here from desert and two mechanics were sitting on wings of the plane to stabilize it.

By the way very good idea

This pictures?




Look, i admit it would be the best, if the devs would give us a lifting device. All i can do now, I landed with retracted gear, and set the flap to 30 deg to lowering the nose (and turn off the head shake in realism). I think it should be stable enough
Anyway, if the plane shaking, then should shake the revi too, but no. It was very stable. We should see a single tracer line, but we have this:



The weirdest picture is this. If a mounted (!) gun (not cannon, just a 7,92 mm machinegun) would be this accurate, then all army use bow and sword until today

[skouras]

i use 250 yards[228 meters] for cannons
it just works great for me
not to close not to far

[VO101_Tom]

Originally Posted by lonewulf

Sorry, none of the above helps me. I'm still not getting it I'm afraid.

vertical convergence == 400 m (Visierschuss)
horizontal convergence == 420 m (Kreuzung)

Ok, as an example, let's use the values listed above. But before that can I just stress that we are only concerned with convergence here, not burn-out and not fusing.
....

I think you mixing things.
Vertical convergence means the distance, when the bullet trajectory will crossing the center of the revi sight.
Horizontal convergence means the horizontal alignment relative to the center line of the Revi.
If the two value is different, then you see the bullet crossing the revi center in vertical, it have differences in horizontal:

this is what you get, if the setting:
MG17 - 400m hor. 400m vert.
MG FF - 200m hor. 400m. vert.

200m:


400m

[lonewulf]

Thanks Thom, I've just now had an opportunity to look at your diagram. That helps explain quite a bit although I'm not convinced that what is provided is all that practical. Essentially the arrangement as described in the diagram provides effective dispersion rather than actual convergence. In the case described, the weapons do not converge at any point. The individual weapons group roughly together at 200m but the MG don't actually converge until 400m at which point the cannon rounds have reached a horizontal spread of 4.5m. At 450m the cannon rounds are probably about 15-20m apart. I'll have to go back to the information provided by Varrattu but I'd have thought to be used effectively you would have to know the exact trajectories of the 7.92 and the 20mm at given ranges. For example, at 200m the weapons all group roughly the same but at an undisclosed distance above the line of sight. So essentially at the point where the projectiles are at their closest, they are also striking above the target. If that's a few cm that's fine but given the low velocity of the 20mm FF cannon compared to the higher velocity 7.92 mm round that seems unlikely. And given that physics are what they are, only certain figures could be used as vert. and horizontal values. If you used something else, the trajectory of the weapon would be distorted, I'd have thought.

Anyway, thanks for the info. I suspect that answers my questions.

[vranac]

Originally Posted by VO101_Tom

This pictures?


Look, i admit it would be the best, if the devs would give us a lifting device. All i can do now, I landed with retracted gear, and set the flap to 30 deg to lowering the nose (and turn off the head shake in realism). I think it should be stable enough
Anyway, if the plane shaking, then should shake the revi too, but no. It was very stable. We should see a single tracer line, but we have this:

Yes,that picture.
I agree with you, but look carefully at 0.06 and 0.11 at your video.It looks
to me that plane moved a bit, because of that I asked you did you look that track from outside view.

I noticed that especially with cannons momentum they provide is huge.
I have one track with damaged one wing and cannon which shows how hole on the wing impact flight(had to compensate with rudder)
Then I tried to shoot at passing plane.Result was a disaster

Originally Posted by VO101_Tom

The weirdest picture is this. If a mounted (!) gun (not cannon, just a 7,92 mm machinegun) would be this accurate, then all army use bow and sword until today

strange

@lonewulf
Best way for you is to try it yourself. Shot at planes with icons enabled to see distance and record track.You will see where tracers cross.
Then set it to distance on which you shot most of the time.

It is not easy to shoot precise with cannons but I know some guys that damaged my plane hard 95% when they pull the trigger )))
And that from very hard angles.
Practice,practice,practice...))