Rifle Scopes 1 MIL - Splitting Hairs

[Killer Spade 13]

OK, I've visited several different sites studying the milliradian.

I've noticed that there seem to be 3 different values used for the milrad; 3.4", 3.5" and 3.6".

WHICH IS THE CORRECT ONE to use with a milrad scope?

 

[DannySeesUSMC]

Re: 1 MIL - Splitting Hairs

Here is a good one

 

[timelinex]

Re: 1 MIL - Splitting Hairs

its milrad is as its name implies its 1/1000 of any distance.

So if your shootings at 1000 yards, 1 milrad is 1/1000 of it, which is one yard. One yard is3 feet which is 36 inches. So at 100 yards, its 1/10 of that or 3.6 inches.

 

[springer01]

Re: 1 MIL - Splitting Hairs


^^ Good Read!

I think what you might be confusing is 1 mil=3.6" at 100, and 1mil=3.438 moa

 

[Drifter™]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">OK, I've visited several different sites studying the milliradian.

I've noticed that there seem to be 3 different values used for the milrad; 3.4", 3.5" and 3.6".

WHICH IS THE CORRECT ONE to use with a milrad scope?

At 1000 yards a 0.1" difference equates to 10 inches. Sizeable difference. </div></div>

If you're talking about 100 yards regarding the 0.1" differences in your sources of information, the corresponding difference at 1000 yards would be only 1", and not 10".

Or maybe my math is flawed, or perhaps I'm misunderstanding your post...

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: springer01</div><div class="ubbcode-body">
^^ Good Read!

I think what you might be confusing is 1 mil=3.6" at 100, and 1mil=3.438 moa </div></div>

OK, in the link given, the cross hairs are set up with mil dots.
As shown in the illustration, the mil dots are given to be equally spaced, correct?

If in the first example coming down from the top of the scope 1 mil = 3.438". Now the second example down shows that 1 mil is also equal to 3.6"??? 3.6 is not equal to 3.438, I don't care where ya studied mathematics . . .

So, at 100 yards,using a scope graduated in mil dots, given that I have a 100 yard zero, if I hold over 1 mill, and all other things being equal, will the bullet impact be 3.438" or 3.6" high?

You're right,Drifter, one decimal place to far to the right, but the question still begs, which one is correct?

 

[acttacus]

Re: 1 MIL - Splitting Hairs

That's because you're forgetting that 1moa is not exactly 1" at 100yds~

1 moa = 1.047197580733" at 100yds

so 1mil = 3.438moa = (1.04719758" x 3.438moa) = 3.600" at 100yds = 36" at 1000yds


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: springer01</div><div class="ubbcode-body">
^^ Good Read!

I think what you might be confusing is 1 mil=3.6" at 100, and 1mil=3.438 moa </div></div>

OK, in the link given, the cross hairs are set up with mil dots.
As shown in the illustration, the mil dots are given to be equally spaced, correct?

If in the first example coming down from the top of the scope 1 mil = 3.438". Now the second example down shows that 1 mil is also equal to 3.6"??? 3.6 is not equal to 3.438, I don't care where ya studied mathematics . . .

So, at 100 yards,using a scope graduated in mil dots, given that I have a 100 yard zero, if I hold over 1 mill, and all other things being equal, will the bullet impact be 3.438" or 3.6" high? </div></div>

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

OK, I was having a brain fart.
A scope can't have mil dots that are both milradian and MOA.

Duuhhh . . . .

Nevermind, I'll just go back to my cave now.

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

Just not having a good day on the mental side of things.
Need more coffee.

 

[Pat M]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">OK, I was having a brain fart.
A scope can't have mil dots that are both milradian and MOA.

Duuhhh . . . .

Nevermind, I'll just go back to my cave now. </div></div>


On some first focal plane scopes the power knob has both Mil & MOA marked, hope that helps your brain

4th picture down on this article
http://corksoutdoors.com/blog/wonders-optics-4-14x50-product-review/

 

[gstaylorg]

Re: 1 MIL - Splitting Hairs

A milliradian is an <span style="font-style: italic">angular measurement</span> that subtends an arc of 1/2000 x pi of a circle, roughly 1/6283.2 of a circle. It is <span style="text-decoration: underline">not</span> a measure of distance. The length of the arc subtended by one milliradian obviously changes as the radius of the circle gets larger. Thus, the arc length subtended by a milliradian in a scope reticle, or "distance or spread" as it is commonly referred to, increases as the distance from the observer/shooter increases.

A circle of radius 1000 yd has a circumference of [2 x pi x 1000 yd x 36 inches/yd] = 226,194.67 inches. An angle of one milliradian subtends an arc of roughly 1/6283.2 of this circle, or exactly 36 inches when the numbers aren't rounded off. Similarly, a milliradian subtends an arc of 3.6 inches at a distance of 100 yd, where the radius of the circle has been decreased by a factor of 10 as compared to 1000 yd.

The same type of calculations hold true for MOA as an angular measurement. One MOA subtends an arc of 1/21,600 the circumference of any circle [1/(360 degrees)(60 minutes/degree)]. Neither milliradians or MOA are an actual measure of distance (spread) unless the range to the target (ie. radius of the circle) is specified.

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

Yeah, I got all that. Was just being thick headed this morning. Didn't give the diagram the proper amount of thought before I put my mouth in gear without putting my brain in motion.

It's all perfectly clear.

Thanks, Guys . . .

 

[ctressler]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gstaylorg</div><div class="ubbcode-body">A milliradian is an <span style="font-style: italic">angular measurement</span> that subtends an arc of 1/2000 x pi of a circle, roughly 1/6283.2 of a circle. It is <span style="text-decoration: underline">not</span> a measure of distance. The length of the arc subtended by one milliradian obviously changes as the radius of the circle gets larger. Thus, the arc length subtended by a milliradian in a scope reticle, or "distance or spread" as it is commonly referred to, increases as the distance from the observer/shooter increases.

A circle of radius 1000 yd has a circumference of [2 x pi x 1000 yd x 36 inches/yd] = 226,194.67 inches. An angle of one milliradian subtends an arc of roughly 1/6283.2 of this circle, or exactly 36 inches when the numbers aren't rounded off. Similarly, a milliradian subtends an arc of 3.6 inches at a distance of 100 yd, where the radius of the circle has been decreased by a factor of 10 as compared to 1000 yd.

The same type of calculations hold true for MOA as an angular measurement. One MOA subtends an arc of 1/21,600 the circumference of any circle [1/(360 degrees)(60 minutes/degree)]. Neither milliradians or MOA are an actual measure of distance (spread) unless the range to the target (ie. radius of the circle) is specified. </div></div>

Well said, the varying values of a mil rad come from the way some branches of our military choose to round.

 

[Spuhr]

Re: 1 MIL - Splitting Hairs

That is the really good thing about metric, as the Mrad fits into the metric system better than into the imperial system due to teh subtensions.

On 572 meters is 1 Mrad 57 centimeters.

It's just not that it's a 1/1000 of the distance, it's actually something that metric thinking people directly can relate to, without maths.....

So I know people are getting mad, when we call mil dot a metric reticle, but for all of us metric people, it is really a metric reticle....

Håkan

 

[ctressler]

Re: 1 MIL - Splitting Hairs

Spuhr, you are so right. I wish could bring myself to switch all the way to metric. The entire scientific community uses metric, but we Americans find it slightly unpatriotic.

 

[bigwheeler]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ctressler</div><div class="ubbcode-body">Spuhr, you are so right. I wish could bring myself to switch all the way to metric. The entire scientific community uses metric, but we Americans find it slightly unpatriotic. </div></div>

Has nothing to do with tradition or patriotism. We took degrees minutes and seconds from navigation and surveying. With todays electronics it hardly matters
anymore. I started with mils in the 90's and switched to iphy. Mils came from the
French. The military has a habit of inventing it's own crap. In this case it works,
usually it's 20 years behind the times.

 

[Rafael]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pat M</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">OK, I was having a brain fart.
A scope can't have mil dots that are both milradian and MOA.

Duuhhh . . . .

Nevermind, I'll just go back to my cave now. </div></div>


On some first focal plane scopes the power knob has both Mil & MOA marked, hope that helps your brain

4th picture down on this article
http://corksoutdoors.com/blog/wonders-optics-4-14x50-product-review/

</div></div>

Of course, you meant to say that some "Second-Focal-Plane" scopes have power rings marked for both MOA and mils. All First-Focal-Plane scopes reticle subtension values remain the same.... no matter the power setting.

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

OK, Guys, let it rest!!! I understand the errors or my math and the errors or my ways!!! Geeeeeeezzzzzzzzzzzzzzzz ! ! ! ! !

I'm going with mil/mil and zeroing at 200 meters and getting away from inches and yards.

Doesn't require any further discussion.

I understand it !!!!

 

[Killer Spade 13]

Re: 1 MIL - Splitting Hairs

OK, Guys, let it rest!!! I understand the errors or my math and the errors or my ways!!! Geeeeeeezzzzzzzzzzzzzzzz ! ! ! ! !

I'm going with mil/mil and zeroing at 200 meters and getting away from inches and yards.

Doesn't require any further discussion.

I understand it !!!!

The ratio of 1:1000 works quite nicely for me.

 

[Rob01]

Re: 1 MIL - Splitting Hairs

Good luck finding ranges in meters if you go anywhere to shoot. Plan on having to convert to yards. Also plan on getting target sizes in inches and having to convert to cm. That's why I use mils and all my data is in yards.

Also I would recommend a 100 yard/meter zero as everywhere you dial will be up. No need to dial below your zero at any point.

 

[Graham]

Re: 1 MIL - Splitting Hairs

There's nothing metric about Mils.

BTW:

1 Mil = 3.6" at 100
1 MOA = 1.047" at 100
3.6 divided by 1.047 = 3.438
So 1 Mil = 3.438 MOA

 

[Spuhr]

Re: 1 MIL - Splitting Hairs

Look at your conversion sheet down there and compare it to this.

1 mil=1dm at 100
1 mil=1m at 1000
1 mil=2dm at 200
2,5mils=1 meter at 400
3 mil=1,8meters at 600

The big difference and what makes mil more metric than imperial is that the metric system fits right into the mil system, something that not the imperial does.

And this is likely why some manufacturers (S&B)marks their scopes with 1cm per hundred meter, instead of 0,1 mil....

Håkan


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">There's nothing metric about Mils.

BTW:

1 Mil = 3.6" at 100
1 MOA = 1.047" at 100
3.6 divided by 1.047 = 3.438
So 1 Mil = 3.438 MOA </div></div>

 

[Rob01]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Spuhr</div><div class="ubbcode-body">

And this is likely why some manufacturers (S&B)marks their scopes with 1cm per hundred meter, instead of 0,1 mil....

</div></div>

Not all are marked cm. I have an older one that is but my two newer models are 0.1 mrad.

 

[ctressler]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">There's nothing metric about Mils.</div></div>

Nobody is saying that MILs are metric, we are just pointing out that using meters rather than yards lends well to the MIL system.

 

[Rob01]

Re: 1 MIL - Splitting Hairs

Maybe nobody is here but it always comes up that people say mils are metric. The metric system being a 10 based system does lend itself to mils but we are also in the US where you will find most target ranges in yards and if you go to competitions you will find most all distances in yards and get target sizes in inches so you will have to be doing alot of converting back if you do your data in meters with cm target sizes when you can just use mils with inches and yards and do that just fine.

 

[Graham]

Re: 1 MIL - Splitting Hairs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ctressler</div><div class="ubbcode-body">... using meters rather than yards lends well to the MIL system.</div></div>That's the myth that I am trying to point-out: It doesn't matter what units you range in, there's no difference in convenience.

 

[Rob01]

Re: 1 MIL - Splitting Hairs

Graham is right about ranging with either system. You either use 27.78 constant with yards or 25.4 to get meters. Neither is easy to do in the head.

 

[Spuhr]

Re: 1 MIL - Splitting Hairs

Graham is absolutely wrong.
noone is used to calculate in the head of 1/1000 of a yard, as with such small measures as you then uses inches or parts of inches.
In metric we still uses measueres that fits to the milsystem without calculations.

Håkan

 

[Lowlight]

Re: 1 MIL - Splitting Hairs

He is not wrong, just nobody is qualifying their statements.

If you range in inches with a mil based scope it doesn't matter which you use, yards or meters.

If you range in centimeters or millimeters then meters is easy to do in your head.

It matters and nobody here is explaining themselves completely.