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View Full Version : MK108/Mg131 Convergence



weaselwagon1
03-29-2007, 04:25 PM
In a 109,is there a convergence with the Mg's and cannon?In fact is there any convergence on Aircraft armed with Cowl mounted/hub mounted weapons?Weapons that are mounted on the central axis of the plane shouldnt seem to need convergence on the vertical since any useful shooting would usually be done well within the limits of the trajectory of the weapon,even with the low velocity rounds of the MK 108.i seem to miss shots from the 6 oclock straight behind from close range that I dont miss at significantly longer distances.The bore of the 3 weapons are close enough to permit level bore sighting with no regard to elevation but why i am i missing at this particuale range and position?

berg417448
03-29-2007, 04:28 PM
There is a vertical component to convergence. If you fail to take this into account you may miss.

This is for an M-16 but it illustrates the point:
http://www.globalsecurity.org/military/library/policy/army/fm/3-22-9/image1608.jpg

VW-IceFire
03-29-2007, 04:29 PM
There is vertical convergence as well...when you fire then the round will arc and at convergence will pass through the center point on the gunsight from when you fired it. Its certainly not as significant as wing mounted convergence but its there.

The MK108 isn't very flat at all...so you may want to determine the best distance that you're hitting at and bring the convergence in to that spot (or push it out).

weaselwagon1
03-29-2007, 04:37 PM
Anyone know of a chart for actual drop for the 108?Might be similar to a pistol round in drop since pistols generally are sub 2000 fps like the 108 but then theres weight,profile,etc

weaselwagon1
03-29-2007, 04:38 PM
we need a 108 chart,that 5.56 round at 3000 fps is way out of the ballpark...

weaselwagon1
03-29-2007, 04:42 PM
Your chart reads that zero at 175 yards,is that for a shorter M4 or a full length 16a2?

berg417448
03-29-2007, 04:54 PM
Originally posted by weaselwagon1:
Your chart reads that zero at 175 yards,is that for a shorter M4 or a full length 16a2?


That chart shows 25 meter zero which makes it on at 300 as well.

Oh...and it is for an M4.

FritzGryphon
03-29-2007, 04:58 PM
I just tested with the Me-262, attacking B-29s from 1000m range.

With a few hundred rounds expended, I didn't get one single solitairy hit. So I moved to 800m, and still I didn't manage to score a hit. Then I moved to 700m, and boom, the bomber blows apart immediately.

Upon watching the track, I realize that the MK108 projectile only survives long enough to travel about 700m. After that it ceases to exist. Hits beyond this range are impossible.

The same problem is present on the MG131Z, which only travels about 400m before vanishing.

I understand the projectiles must be eliminated in order to preserve performance, especially where there are a lot of bullets at one time. But for no reason should the range be so short as to cause misses, where otherwise would be hits.

weaselwagon1
03-29-2007, 08:41 PM
Berg that chart then means that at 175yds you should be aiming about 7 inches under right?

weaselwagon1
03-29-2007, 08:46 PM
or is that 7 inches over?

VW-IceFire
03-29-2007, 10:05 PM
Originally posted by FritzGryphon:
I just tested with the Me-262, attacking B-29s from 1000m range.

With a few hundred rounds expended, I didn't get one single solitairy hit. So I moved to 800m, and still I didn't manage to score a hit. Then I moved to 700m, and boom, the bomber blows apart immediately.

Upon watching the track, I realize that the MK108 projectile only survives long enough to travel about 700m. After that it ceases to exist. Hits beyond this range are impossible.

The same problem is present on the MG131Z, which only travels about 400m before vanishing.

I understand the projectiles must be eliminated in order to preserve performance, especially where there are a lot of bullets at one time. But for no reason should the range be so short as to cause misses, where otherwise would be hits.
Hispano has the same problem. The .50cal, the UBS, MG151, and some of the other weapons seemingly go on forever.

BBB_Hyperion
03-30-2007, 12:27 AM
Here is a Chart for Mk108 MG131

http://img5.imagevenue.com/loc572/th_36012_Mk108drop_122_572lo.JPG (http://img5.imagevenue.com/img.php?image=36012_Mk108drop_122_572lo.JPG)

Kurfurst__
03-30-2007, 12:32 AM
Originally posted by VW-IceFire:
Hispano has the same problem. The .50cal, the UBS, MG151, and some of the other weapons seemingly go on forever.

It might be two different things, IIRC there wasa former discussion on this : the tracers burn time vary round to round, but even after its gone the "invisible" rounds are still there and the distance limit is probably the same. The larger HE rounds usualy had a self destruct fuse for long distances. It could be possibly checked with firing at ground targets at known distance using arcade mode on.

13mm and MK 108 on G-6/U4, via the Lair - the engine cannon was mounted at an upward angle and had very similiar ballistic path with the HMGs this way at practical distances from ca 150 meter. The MG 151 figures are for gondies.

http://109lair.hobbyvista.com/techref/manuals/109g/g6u4/g6u4_t8-30.jpg

FritzGryphon
03-30-2007, 01:40 AM
the tracers burn time vary round to round, but even after its gone the "invisible" rounds are still there

Not the case, at least with the MK108, and probably the others.

Beyond the vanishing point, no damage is ever caused, nor do hits appear on the ground. It is simply a particle life, like any other particle.

F19_Ob
03-30-2007, 04:00 AM
Originally posted by FritzGryphon:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">the tracers burn time vary round to round, but even after its gone the "invisible" rounds are still there

Not the case, at least with the MK108, and probably the others.

Beyond the vanishing point, no damage is ever caused, nor do hits appear on the ground. It is simply a particle life, like any other particle. </div></BLOCKQUOTE>

I agree with Fritz.

A few patches ago I tested the range of several weapons.
The german cannons reached 800m.
I was flying the il-2's a lot then and the 23mm cannon reached 1200m and the light mg's reached about 1000m.

I used to pick off extending or running 109's around 800-1000m. I usually hit them on top of their climb when they were standing still.
The russian guns have ,more or less, the best trajectory and rate of fire.
Il-2's also have an astonishing ammoload.

jermin122
03-30-2007, 05:42 AM
Hispano has the same problem. The .50cal, the UBS, MG151, and some of the other weapons seemingly go on forever.
Got track? Hispano is very deadly when shooting at 600m, AFAIK.