Author Topic: gun convergence (Read 1329 times)

101ABN · « **on:** March 25, 2004, 05:00:41 AM »

I normally fly a P38, what is the best distance to set the gun convergence. Last night i was right on someones butt and i opened up with the guns and only smoked him. he was in my sights for quite awhile too.

Max · « **Reply #1 on:** March 25, 2004, 07:06:29 AM »

The P-38's guns are nose mounted, and do not converge. What were you aiming at and at what distance? Being "up someone's butt" on your FE may have been "seen" differently from the NME's FE due to web lag.

DmdMax

Ghosth · « **Reply #2 on:** March 25, 2004, 08:41:13 AM »

Actually Dmax, thats all done on the shooters FE, so what he's sees is what he gets when it comes to shooting.

However anytime your dealing with .50 mg's you need to remember you can't be hosing that fire all over.

You need to stay in the same spot for a sustained burst to cause catastrofic failure.

As for the cannon, if it was pass 300 distance those rounds probably fell way below him.

TequilaChaser · « **Reply #3 on:** March 25, 2004, 09:43:20 AM »

I would like to know if the convergence of nose mounted guns still play a role in your aiming. although you are not converging in the same sense as wing mounted guns, you still should be converging the up and down aiming of the nose mounted guns to a degree, so that the pilot being seated above the guns slightly, has the correct gun angle at a set distance? what is the thoughts of others on this issue?

Delirium · « **Reply #4 on:** March 25, 2004, 04:08:33 PM »

I haven't seen any change in the bullet drop between low and high range convergence on the P38. To note, the bullet drop on the P38 is one of the lowest of all aircraft. I can consistently get pings and kills 1.2 out (enough to make the Lgay7 reverse) with an odd ping/kill as far as 1400.

Ghost, keep in mind the muzzle velocity is different for many planes even though they are carrying MGs and cannon of roughly the same size. A German 20mm on a Dora has alot more of a drop than the British 20mm on the Typhoon for example.

Soulyss · « **Reply #5 on:** March 25, 2004, 06:09:16 PM »

In theory at the guns convergence range the bullets should land in the center of your cross hairs. So increasing your convergence range is changing the elevation of the bullet stream slightly.

*edit* I think.

Ecliptik · « **Reply #6 on:** March 25, 2004, 08:52:09 PM »

I believe that was true in reality, however some trials in with it in Aces High suggests that this is not the case. Setting convergence of 650 and then firing at a target from 650 yards dead six with the fuselage right on the dot will not result in hits.

Flit · « **Reply #7 on:** March 25, 2004, 08:59:33 PM »

acually., I think the convergence is where the bullet paths from All your guns meet (as in converge)
So, changing the convergence does not change the elevation of the guns, it changes the angles of the guns slightly on the horizontal plane

SixxGunn · « **Reply #8 on:** March 25, 2004, 09:31:20 PM »

When I fly the P38 the bullet stream from my point of view is a touch above the gunsight pipper, regardless of gunsight used.

I now aim just below target aircraft and score hits.

Of course I'm cross eyed and blind in one eye so that might be it.

Ecliptik · « **Reply #9 on:** March 25, 2004, 10:22:22 PM »

Quote

So, changing the convergence does not change the elevation of the guns, it changes the angles of the guns slightly on the horizontal plane

We did know that, but I think Soulyss was commenting on the fact that many aircraft in the war had their guns angled up slightly to account for bullet drop and place the point of impact on the crosshairs for a certain range.

Ghosth · « **Reply #10 on:** March 26, 2004, 08:12:07 AM »

TC

Disclaimer I have not tried this out in person. This is an untested theory. I have no proof that there is any truth to it.

However ...........................

heard a guy (longtime ah pilot) mention to someone in main the other day that if he wanted his cannons to hit at the same point as his mg's he should set the cannon convergience 50 feet farther than the mg's.

Please feel free to prove this for me.

I believe he was talking 600 & 650 yards which is rather a LOT longer than I ussually set mine. I come from the "Cannons should be used in close" school.

Let me know what you find please.

TequilaChaser · « **Reply #11 on:** March 26, 2004, 09:20:30 AM »

Quote

Originally posted by Ghosth
TC

Disclaimer I have not tried this out in person. This is an untested theory. I have no proof that there is any truth to it.

However ...........................

heard a guy (longtime ah pilot) mention to someone in main the other day that if he wanted his cannons to hit at the same point as his mg's he should set the cannon convergience 50 feet farther than the mg's.

Please feel free to prove this for me.

I believe he was talking 600 & 650 yards which is rather a LOT longer than I ussually set mine. I come from the "Cannons should be used in close" school.

Let me know what you find please.

I did 2 test, twice Ghosth, 1st test - mg's set at 600 Cannon set at 650, pretty much dead on, with cannon hitting slightly left of bullseye, 2nd test both mg's and cannon set at 650 cannon slight drop and slight left of bullseye. I ran these test offline and used [Shift] X to keep plane centered on the target I had set at 600 for first target and 650 for second target/test.
not much of a drop but some was evident on the cannon burst. surprising note was the cannon hitting just left of the dead center.

(edited after retest) Also, tested with target set at 250 out, almost dead center, target set at 400 out had hits high over dead center, same with 500 out, 600 out dead center, 650 out hits slightly lower, 800 out hits dramatically lower. all above distances was using convergence of 600 on mgs and 650 on cannon.

Elysian · « **Reply #12 on:** March 26, 2004, 07:38:26 PM »

Don't quote me on this but I seem to remember HT saying that guns *do* elevate in response to extending the convergence range in an old thread.

I use 400 for .50 cal/hispanos and 350 for LW, works fairly well.

Ghosth · « **Reply #13 on:** March 27, 2004, 08:53:53 AM »

So basicly TC it looks like its working huh.

Will have to give this a try I think.

What planes did you use to test on the shooter end?

TequilaChaser · « **Reply #14 on:** March 27, 2004, 10:23:14 AM »

Quote

Originally posted by Ghosth

What planes did you use to test on the shooter end?

I used the P38 as my platform, I was thinking of using the 109 also, but figured with the different characteristics of the cannons in the 109 , they would drop off even more.