Why you should choose MIL, not MOA

[Hohn]

Now, this assumes you are twiddling turrets. If you are set-and-forget kind of guy, pick what you prefer as it doesn't matter.

The short answer is this: A radian is inherently unitless. It is a simple ratio of arc to distance. A milliradian just means the arc length is 1/1000th of the distance. At 100 yards, it's 0.1 yards.

Best of all, a milliradian allows easy decimal conversions. Just slide the decimal point. You're at 100 yards and want to know what 0.1 Mil is? It's 1/10,000th of the distance, or 0.01 yards (just move the decimal four places). So each click of your turret is 0.01 yards (.36 inches) at 100y. Easy right?

What about MOA? Can any of us think in terms of minutes of angle? It doesn't use powers of ten. And the approximation of 1" at 100y is just an approximation, that extra 0.047" can actually add up. So because we like "inches" as comfort unit, we accept unncessary error and difficulty in conversion to distance because there's always a unit conversion.

The real power of MIL comes once you get comfortable with metric and learn to think of 0.1 Mil is 1cm at 100m. (again, just slide decimal point 4 places to the left).


This also works well in reverse, as your MIL-hash marked reticle makes for much easier ranging calls. You range something 3 mils tall in your reticle and know that it's about 6ft tall. Well, a mil being a ratio of 1000 means that something 1 ft tall is 1 mil at 1000ft. 6ft tall and 3 mils is 2000 ft. (6/3*1000). 6 mils for a 3ft object means 500ft.



So that's it: easy conversion with no error, with MIL or with MOA get conversions that are either easy or accurate, but never both.

 

[Dean C.]

I use metric anyway , science for the win

 

[Gabriel]

I'll give you my MOA when you pry it from my cold, dead hands.

 

[seedubs1]

Want to buy my old MOA stuff? I've moved to MIL.

I'll give you my MOA when you pry it from my cold, dead hands.

 

[T.Lex]

When MOA is outlawed, only outlaws will have rounding errors.

 

[Hohn]

I use metric anyway , science for the win

Metric fan with dyslexia, UNTIE!

 

[Gabriel]

I use metric anyway

Why do you hate America?

When MOA is outlawed, only outlaws will have rounding errors.

MIL snob!

 

[Hop]

Now, this assumes you are twiddling turrets. If you are set-and-forget kind of guy, pick what you prefer as it doesn't matter.

The short answer is this: A radian is inherently unitless. It is a simple ratio of arc to distance. A milliradian just means the arc length is 1/1000th of the distance. At 100 yards, it's 0.1 yards.

Best of all, a milliradian allows easy decimal conversions. Just slide the decimal point. You're at 100 yards and want to know what 0.1 Mil is? It's 1/10,000th of the distance, or 0.01 yards (just move the decimal four places). So each click of your turret is 0.01 yards (.36 inches) at 100y. Easy right?

What about MOA? Can any of us think in terms of minutes of angle? It doesn't use powers of ten. And the approximation of 1" at 100y is just an approximation, that extra 0.047" can actually add up. So because we like "inches" as comfort unit, we accept unncessary error and difficulty in conversion to distance because there's always a unit conversion.

The real power of MIL comes once you get comfortable with metric and learn to think of 0.1 Mil is 1cm at 100m. (again, just slide decimal point 4 places to the left).


This also works well in reverse, as your MIL-hash marked reticle makes for much easier ranging calls. You range something 3 mils tall in your reticle and know that it's about 6ft tall. Well, a mil being a ratio of 1000 means that something 1 ft tall is 1 mil at 1000ft. 6ft tall and 3 mils is 2000 ft. (6/3*1000). 6 mils for a 3ft object means 500ft.



So that's it: easy conversion with no error, with MIL or with MOA get conversions that are either easy or accurate, but never both.

Dude...

Thou shall not shoot on a 100 yard range with a mrad scope!

 

[Gabriel]

What about MOA? Can any of us think in terms of minutes of angle? It doesn't use powers of ten. And the approximation of 1" at 100y is just an approximation, that extra 0.047" can actually add up. So because we like "inches" as comfort unit, we accept unncessary error and difficulty in conversion to distance because there's always a unit conversion

That error adds up to less than a 1/2" at 1000 yards. If that 1/2" is throwing you off at that distance, you're one hell of a shot.


Metric units mean nothing to me, which is why I've stuck with MOA. Talking about mm, cm, meters, or kilometers I have to go back to the nearest US unit of measure and find out how close the metric unit is and work from there. I'm too old to bother switching over and I'm not a commie, so I'll stick with standard US units of measure.

I actually understand how MIL/MIL is more convenient, my brain absolutely cannot get around it, though.

 

[T.Lex]

MIL snob!

I wanted to know what it felt like to be a millenial, so I created a google sheet with a direct link on my phone. Now I don't have to do the math in my head.

Also, I have long trained in the TLAR method of aiming with the Mark I Rev. 1.5 Eyeball (LASIK about a decade ago). "That Looks About Right."

 

[Hohn]

That error adds up to less than a 1/2" at 1000 yards. If that 1/2" is throwing you off at that distance, you're one hell of a shot.


Metric units mean nothing to me, which is why I've stuck with MOA. Talking about mm, cm, meters, or kilometers I have to go back to the nearest US unit of measure and find out how close the metric unit is and work from there. I'm too old to bother switching over and I'm not a commie, so I'll stick with standard US units of measure.

I actually understand how MIL/MIL is more convenient, my brain absolutely cannot get around it, though.

I learned to "speak" metric later in adulthood-- I'm now "bilingual" and can usually ballpark degrees C, m/km/mm, and such somewhat intuitively. I do still struggle with converting kPa/MPa to PSI or PSI to Bar (which is not officially in use as part of SI, but persists with the Germans).

I find CM and MM especially to be pretty intuitive because so many common objects around us are common Metric sizes. A CD, for example, is exactly 12cm.

It helps to use Metric all day every day at work.


And point taken about MOA approximation error being minor. But the point is that it's still error. And needless error at that.


As for MIL at 100y, I have yet to find a need for more precise scope calibration than afforded by 0.1mil clicks. I'm curious to know the condition under which 0.36" per click is too coarse an adjustment, but .25" per click is sufficient.

Especially since I'm shooting a 50y most times when I zero, making a MIL scope 0.18" per click. To the person whose rifle is so accurate he needs 0.05 mil click: congratulations on your achievement.

 

[natdscott]

As for MIL at 100y, I have yet to find a need for more precise scope calibration than afforded by 0.1mil clicks. I'm curious to know the condition under which 0.36" per click is too coarse an adjustment, but .25" per click is sufficient.

Especially since I'm shooting a 50y most times when I zero, making a MIL scope 0.18" per click. To the person whose rifle is so accurate he needs 0.05 mil click: congratulations on your achievement.

You need smaller targets. They make your rifles a lot more accurate.

Now for SINGLE fired shots, in absence of any sighters, and likely with absence of followup, I think you have to be a helluva long way away from many "targets" before you can justify the NEED for tighter than 1/10 Mil. Not too many shooters can hold it under field conditions either.

But in Target use, even with just slings, 1/4 Minute is not fine enough for a LOT of the targets used in the world, and 1/10 Mil will getcha kill't. I'm not wonderful, but even I am good enough to need 1/4 or finer (if I had 'em).

Been there, tried that.


-Nate

 

[Hohn]

You need smaller targets. They make your rifles a lot more accurate.

1/4 Minute is not fine enough for a LOT of the targets used in the world, and 1/10 Mil will getcha kill't.

Been there, tried that.


-Nate

Deleted.

 

[teddy12b]

I'm on the MOA side of the camp, probably for not much more than I learned that first. Also when I range something and it's 400 yards, 1 MOA at 400 = 4" gives me a pretty good ballpark of where I need to be to do a little math in my head.

For me, the biggest selling point of MIL isn't the math, it's the amount of accessories available in that setup. Want a set of binos or spotting scope with a reticle that matches what the shooter is looking through? Then MIL is going to have more options than MOA in the market place. That's starting to change a little, but very slowly.

 

[rhino]

I don't care as long at the reticle and the turrets match.

 

[natdscott]

Deleted.

PM if you want?

 

[Hohn]

I replied to Nate's PM and thought I'd share a perhaps better-written post here exploring the question: how fine do my turrets need to be?

The short answer is this: your turrets need to be fine enough to matter less than your variation as a shooter with a particular rifle and ammo.


Most shooters are familiar with SD as a measure of velocity variation, but we should mostly care about Standard Deviation as it pertains to ammo grouping relative to POA. I offer the simple idea here: if the scope turret adjustment is finer than the SD of your groups, then you are a larger contributor (on average) to shot group variation than your scope zero is.

Here's a quick test to know if you need turrets finer than 0.1 MIL clicks:

1. Shoot 20 rounds of your given ammo through the given rifle at a given POA.
2. Measure the radial distance from the POA to the outer edge of the 2nd worst shot. This gives you the size of the circle that fully contains 19/20 shots.
3. If this is less than twice the size if your scope click adjustment, you need finer turrets. In the case of a 0.1 Mil turret, you'd be putting 19/20 rounds inside a 0.72" circle (entirely within) at 100y.
​

Now, keep in mind, this 20 shot string is just one sample. For you to really, truly need finer scope turrets, you'd need to do this a few times and consistently best the 0.2 Mil barrier to need finer than 0.1 Mil turrets.



The justification behind the idea above is based on:
1) The assumption that group size is normally (Gaussian) distributed around the POA
2) The well-established idea that 2-sigma values (sigma= SD) correlate to 95% of a distribution
3) The idea that SD is the "average error" for a given shooter/ammo/rifle.



One criticism of this approach is the use of 95% confidence. This is pretty stringent and it means that you are pretty certain the scope here is holding you back.


You may elect instead to use a different confidence. And the group sizing and sample become proportionally much more accommodating to the lower standard. If you choose a 68% confidence (round it to 70%), then you'd only need to put 7/10 rounds inside a circle that is the size of the scope clicks.

Is it tougher to put 7/10 rounds inside 0.36" at 100y or to put 19/20 inside 0.72" at 100y? You be the judge. If you can do either one with consistency, then you might need turrets finer than 0.1 Mil.


You might not be surprised to learn that based on this logic, I will never need a turret finer than 0.1 Mil, and I suspect I'm not alone.

 

[Trigger Time]

If you are a new shooter that has never learned anything, learn mil

 

[phylodog]

I've yet to come across a situation where I could have performed better had I been using a MIL scope instead of my preferred MOA. The debate has been going on since they began making MIL/MIL and MOA/MOA scopes. Neither is particularly better than the other, it's essentially the equivalent of speaking two different languages. There have been a lot of advancements in precision shooting in the past decade which have certainly raised the bar but a slant in favor of MIL over MOA or vice versa isn't one of them.

 

[Hawkeye7br]

At the risk of dumbing this down...a MOA scope has 1/4 inch clicks and a mil-dot scope has 1/3 inch clicks. Is that analogy close enough?