Gunsight metrics, or how I learned to love the gunsights!

[Leon_Portier]

Since I did look into the gunsights, I compiled my calculations in a Gunsight Guide!

This Gunsight Guide is made of 3 parts:

- The Leading Chart for deflection shots in the unit of Mil, which is the unit of the Gunsights

- The most common Gunsights, standart Russian Gunsight(left), standart German Gunsight(upper) and P40 Gunsight(N3A)(lower)

- The Range Chart for measuring the distance to different ground and air targets

 

 

Usage:

Leading Chart: Estimate the speed and Angle off of your target, then on the right side of the leading chart use the leading angle below of the weapons you are using. Position the gunsight in the resulting angle. 

Example: You see a I16 going pretty slow going a bit sideways away from you. See lets look on the left side of the chart, choose 250 Km/h and 20° Angle off. That puts us in the third row of the right side of the chart. We want to use the MG17s of our 109, which puts us in the 1st column, so we have to lead 25 Mils! Now we look in the gunights on the very right side!

We use a 109, so Standart German gunsight it is, we see the markings of it are 10 Mil apart, so we lead 2,5 markings and fire. Volltreffer! He is struck with your fire!

 

Note: The values do assume the bullet has the constant speed of the muzzle velocity. That makes the numbers independent to range, the velocity should not slow too much up to 300m. If the target is further away, apply more lead liberally.

 

 

Range Chart: You are in a IL2 tank killer and you have a PZIII sideways of you. You did set your gun convergence to 300m. Looking at the chart, the PZIII is 300 m away when it is 10 Mil large. A look at the gunsight shemes tells us the Russian gunsights markings are 10 Mil apart from each other. So you put the tank in your sights and fire exactly when the tank is right halfway of the first marking on each side. Both shells hit the same spot on the tank, destroying it!

 

 

Printable: https://www.dropbox.com/s/t46dwwwsi1oncmj/Gunsight.pdf?dl=0

(Last update: 19.07.2018)

 

How its is useful:

Air combat: 

- You can check if you are in gun range with the Range Chart

- Improve your accuracy on deflection shots, make your friends think you use a gyro sight!

 

Ground attack:

- Use the Range Chart to fire exactly at the convergence range you set in your plane to hit with pinpoint accuracy, this is especially useful with the Ju87 with the anti tank cannons

 

In closing I have a request: With the American gunsights we have the N3 in the P39, where I dont know if it has the same diameter of the N3A in the P40? Also how about the A20s gunsights?

 

Thanks for reading, Servus!

Edited July 19, 2018 by Leon_Portier

[Requiem]

Had a quick look on my phone. What stood out to me initially is I think your REVI sight picture is wrong in its measurements. I'll have a look at the other stuff when I get home tomorrow.

[Leon_Portier]

8 hours ago, SYN_Requiem said:

Had a quick look on my phone. What stood out to me initially is I think your REVI sight picture is wrong in its measurements. I'll have a look at the other stuff when I get home tomorrow.

 

Thats fair, the diameter of the circle in the German sight is the only thing I had to measure with the ruler, it might be 29 instead of 28 mil in radius. If there are any questions on the path of calculation I´m happy to answer.

Edited July 18, 2018 by Leon_Portier

[LukeFF]

28 mils? That doesn't sound right at all. Everything I've read says the Revi was a 100-mil gunsight.

[Requiem]

18 hours ago, Leon_Portier said:

 

Thats fair, the diameter of the circle in the German sight is the only thing I had to measure with the ruler, it might be 29 instead of 28 mil in radius. If there are any questions on the path of calculation I´m happy to answer.

I'm back home now (Got stuck in South Carolina overnight)

 

There's no need to explain your calculations Leon as I know how to do it but don't have time to check everything. Since I'm lazy and can use Excel I created a spreadsheet using the required math as part of the preparation for my deflection shooting tutorials. Put in any of the required info and it calculates the speed rating of a sight, the required sight radii required at any combo of airspeed/angle off you want, as well as determining range based on the size of the target and the # mils in the sight. All the muzzle velocities and stuff are included, so I'm happy to send my current version to you via PM if you want to verify your math with it. I update it each time I start making a new gunsight tutorial as it's the tool I use to create those Angle Off sight rings you see in my videos and the gunnery supplement.

 

AFAIK the REVI had a diameter of 100mil, which is closely reflected in your chart (105mil), but I believe the  diagram is incorrect. All the research I made told me that for the REVI C 12/D it's diameter was 100 mil, radius of 50 mil, and each tick mark was worth 18 mil. That's why if you examine the REVI we have in-game you won't see the tick marks sync up perfectly with the circle.

 

The easiest way to know though... if the diameter was 56 mil as you propose in the diagram then that would mean a fighter should fill the REVI circle at 56m away in-game (which it won't). Your chart has it correct for the most part.

Search for a Luftwaffe document called "Horrido - Luftwaffe - Schiessfibel". I believe it's around on these forums somewhere or google will help.

 

Regarding the Russian part of the chart... Something is off because you have the same number of mils as the German chart but different range results which doesn't make sense as a 109 and Yak have approximately the same wingspan for example.

 

From a practical point of view for the chart, I would alter it to only reflect what the gunsight would shoot at. I may be reading it wrong, but I see it as the German gunsight ranging German targets and the Russian gunsight ranging Russian targets which seems odd to me.

 

 

Edited July 19, 2018 by SYN_Requiem

[Leon_Portier]

@SYN_Requiem 

Ok, I fixed the Revi sight, I must have measured it wrong. Gotta say the Horrido Schießfibel has a weird way of explaining it in how often the target fits in the circle.

Range chart is redone as well.

Edit: Thanks btw!

Edited July 19, 2018 by Leon_Portier

[Requiem]

2 hours ago, Leon_Portier said:

@SYN_Requiem 

Ok, I fixed the Revi sight, I must have measured it wrong. Gotta say the Horrido Schießfibel has a weird way of explaining it in how often the target fits in the circle.

Range chart is redone as well.

Edit: Thanks btw!

No worries Leon, happy to help!

[sniperton]

On 7/17/2018 at 10:56 AM, Leon_Portier said:

- The most common Gunsights, standart Russian Gunsight(left), standart German Gunsight(lower) and P40 Gunsight(N3A)(right)

Please check, German appers to be upper right, P40 lower right

[Leon_Portier]

1 minute ago, sniperton said:

Please check, German appers to be upper right, P40 lower right

Done!