HiTech, you may check real MG-FF dispersion here

[GODO]

HoHun, If you have a dispersion of 6 mils at 100 yards with a gun, that dispersion would increase further than 100 yards more and more. In your example I can imagine 21 mils dispersion at 700 yards starting with 6mils at 100 yards, that considering dispersion inducted by gun alone.

[HoHun]

Hello again,

Here's the corresponding diagram for a nose-mounted MK108.

[HoHun]

Hi Godo,

>HoHun, If you have a dispersion of 6 mils at 100 yards with a gun, that dispersion would increase further than 100 yards more and more. In your example I can imagine 21 mils dispersion at 700 yards starting with 6mils at 100 yards, that considering dispersion inducted by gun alone.

Hm, mil is a polar reference system, so the dispersion induced by barrel oscillation should stay the same expressed in mils downrange.

There might be aerodynamic effects I'm not accounting for, though.

Regards,

Henning (HoHun)

[GODO]

Ok HoHun, lets say the dispersion circle would be about 3 times bigger at 700 yards than at 100 yards.

[HoHun]

Hi Godo,

>Ok HoHun, lets say the dispersion circle would be about 3 times bigger at 700 yards than at 100 yards.

Through aerodynamic effects, that is?

Regards,

Henning (HoHun)

[GODO]

Originally posted by HoHun
[BThrough aerodynamic effects, that is?
[/B]

No, due dispersion inducted by guns alone. Then we can add dispersion due temperature, wing, aerodynamics, etc, but all these factors may affect the same way to every round. The movements of the guns in their mountings generate a cone of dispersion starting at soon as the bullets exit the guns, that is, we have rounds with very similar, but, in fact, different trajectories along these dispersion cones.

[HoHun]

Hi Godo,

>No, due dispersion inducted by guns alone.

Hm, I fail to understand how that would increase the mil size of the dispersion downrange.

(It could be a geometric effect due to the parabolic trajectories, but that affects only elevation, and would be noticable only far beyond the ranges we're interested in.)

In short, I think the gunfire should disperse in a cone, while the way I understood your statement, it should disperse in a trumpet shape with dispersion increasing downrange.

Is that idea correct?

Regards,

Henning (HoHun)

[GODO]

Originally posted by HoHun
Is that idea correct?

Absolutely, and the trumpet example was perfect (<- first time I use that ugly emoticon).

[HoHun]

Hi Godo,

>Absolutely, and the trumpet example was perfect

I see :-)

Do you have a mathematical function describing the trumpet?

From 100 m; 1.9 mil to 700 m; 5.7 mil I get dispersion ~ range^0.56.

Is the downrange dispersion always proportional to the initial dispersion? I. e. does

100 m; 1.9 mil to 700 m; 5.7 mil

translate to

100 m; 6.0 mil to 700 m; 18.0 mil for the wing-mounted Brownings?

Regards,

Henning (HoHun)

[GODO]

Current AH 109 nose mounted mk108 dispersion with target at 100 yards:

[moot]

Mandoble, you made that test standing still, right?

[Wotan]

fyi that center circle on the .target is 20ft dia, the next 40 then 60 etc....

[hitech]

Need some one to check my calcs and estimations on the targets range.

The target is Aproximatly 8' accross. I.E. 4' center to edge


Dimention on the 109 tail is 4.9' center line to edge.

From the picture the 109 tail is 144 pixels center to edge.

Target is 12 pixels center to edge.

That would give a tangent of aproximatly 0.1

Hence the target is apox 40' - 50' away.


Radius of dispersion on the target is aprox 6" at 50'

At 100 yards that would translate into   3 feet

Per the 100 yard test in ah it shows a radius of about 2' at 100 yards.

Did I miss somthing?


HiTech

[GScholz]

That target is about 150 meters away.

[ra]

50' would be only 1 1/2 wingspans.  That target must be farther away than that.