MOA, MIL or Both?

The most common questions I get asked by friends looking to purchase a new rifle scope is what is the difference between MOA and MIL, second focal plane and first focal plane reticles, which would I recommend and why. For the longest time my answer to them has been relatively simple and vague to say the least. If you are more familiar with the imperial system and inches then go with MOA. If you are more familiar with the metric 1/10 based system then opt for MIL. As for SFP and FFP reticles, choose SFP if you want a reticle that doesn’t change size as you adjust magnification and FFP if you want a reticle who’s sub-tensions are true to scale no matter what magnification you are on.

Now personally speaking, I have always been an MOA guy myself because I grew up in a country where everything is based on the imperial system and therefore I am more comfortable dealing in inches and fractions of an inch as opposed to the 1/10 scale of the metric system. Over the years however, I couldn’t help but notice that a lot of long range and tactical shooters here in the USA seem to prefer the MIL scopes despite the fact that we all use the imperial system. This has always puzzled me and I’ve always wondered what it was that I was missing.

So before I get into what I discovered in my quest to understand what made MIL scopes so popular among shooters in certain shooting disciplines let’s first take a look at the basic difference between these two systems of angular measurement. As I mentioned before, one is closely related to inches while the other is based on a 1/10 scale factor like the metric system. For example 1MOA is approximately 1” at 100 yds and 1MIL is 10cm at 100 meters. You get my point.

A minute is just a fancy word for one-sixtieth (think about 60 minutes in an hour). Well, that's the same as saying one minute is a sixtieth of an hour. This minute is gonna be the sixtieth of the angle that is on the circle of 360 degrees. So, the sixtieth of one of those degrees is one minute of angle. It ends up being about 1.0400 inches at 100 yards. Keep in mind that it’s not a size at a certain distance, but rather it's an angle that we're making in the scope that ends up translating to a certain size at a certain distance.

With minute of angle (or MOA for short), one click on your turret is approximately equal to 1/4 MOA or a 1/4” shift of your reticle @ 100 yds. on most scopes and sometimes as low as 1/8 MOA on others. This has always made it easy for me to make calculates in my mind because I’m very familiar with inches.

MILs, like MOA, is also an angular measurement and the length it represents also increases proportionally with distance. For example, 1 mil at 100 meters equals 10cm or 3.6” at 100 yds and 20cm at 200 meters or 7.2” at 200 yards.
Now before we go any further let’s take a look at some rough numbers to put things into perspective. For comparison purposes we will convert both MOA and MILS to inches and although 1MOA = 1.047”, we’ll round that down to 1” for simplicity purposes.

1 MOA = 1” @ 100 yds & 1 click = .25 “ shift

1 MIL = 3.6” @ 100 yds & 1 click = .36” shift

From this we can see that a MOA scope will allow you to make slightly finer adjustments especially if your scope has 1/8 MOA adjustments which would translate to 1-click moving your reticles roughly only .125”!! This is useful for those who are trying to fine tune their reticle for extremely high level precision shots on small targets such as when shooting bench rest and extreme bench rest matches where you are aiming for a 1/4” X-ring @ up to 100 yds. away! Also, what’s important to note is that in this type of shooting, second focal plane (SFP) reticles are normally preferred because you can turn up the magnification on your scope to zoom in on your target and the size of your reticle remains the same as opposed to first focal plane (FFP) reticles that grow and get get thicker as your magnification increases thereby covering up more of your target. Usually thin reticles are preferred as well as they cover up less of that 1/4” X-ring when zoomed in at 100 yds! My scope of choice for bench rest and extreme bench rest is a Delta Optical Stryker HD 5-50x56 in MOA with a SFP reticle. The floating center dot is so small that I can still see the entire 10 ring at 100 yds on 40x magnification and at 40x my reticle sub-tensions are true to scale. It also has an illuminated center dot for those rare instances when I may be shooting against dark background that makes it difficult to see my reticle.

Now getting back to the topic at hand, I recently started to venture into the world of precision rifle shooting with high power airguns. With the accelerated growth and technological advancements in the airgun industry we are now able to combine the power and efficiency of modern airguns with the increased ballistic performance of airgun specific slugs. This combination now allows airgunners to push the boundaries of what is possible with an airgun. Basically we can now shoot targets much farther away with much more accuracy and precision than was ever possible with traditional drag stabilized diabolo pellets. This has ushered in a new era for airgunners with organizations such as PRS and NRL opening the doors to airguns to compete against rimfire rifles at distances previously unimaginable.

So what does all this have to do with the topic at hand you say?? Well, it’s pretty simple actually. I was looking at a typical NRL event the other day and at the stages and course of fire for each stage and while doing so I was asking myself what characteristics I would want in a scope for this type of shooting. While making a checklist of what I wanted, It quickly became apparent that what I was missing all along was the fact that different scopes are designed for different applications and the decision on which type of scope to buy had less to do with it being more similar to inches and fractions of an inch or a 1/10 scale factor used in the metric system but more so on the characteristics and feature set of the scope and how well that feature set aligns with what you need it to do for you as a shooter.

So let’s take a look at PRS and NRL shooting for example. In these types of events you are engaging multiple targets of different sizes and different distances all while on the clock. As you move down the course of fire you are engaging targets further and further away and therefore you are constantly dialing for elevation and windage. Since you are on the clock time is of essence so the less time you spend dialing the better right? Here is where the MIL scopes shine. It’s a lot quicker to dial 2 MILS than it is to dial 7 MOA so that’s time saved every time you have to adjust for elevation and windage. The finer adjustments of MOA are no longer of great importance as the sizes of the targets are much larger and that extra level of precision in reticle adjustments is no longer necessary. The targets are not 1/4” at 100 yds anymore either so having a thin reticle that doesn’t get thicker with increased magnification is no longer a priority. Instead, the ability to have your reticle sub-tensions remain true to value at any magnification you may be in is now basically a must have especially in stages where you have to use your reticle to range your targets. So as you can see, the feature set of a scope geared towards one particular style of shooting or application may be significantly different to one designed for another style of shooting or application. Different tools for different jobs… Now when someone asks me what scope I would recommend, my answer is “it depends….”.

My current PRS gun is now topped with a ValdadaOptics Recon G2 4.8-30x56 in MIL (who would have thought??) with a FFP reticle and a 40 mm main tube allowing an elevation adjustment range of 43 MILS or 150 MOA. Plenty for shooting airgun slugs out past 300 yds. So I now have both MOA and MIL scopes with both SFP and FFP reticles. The 1/10 scale is actually pretty simple to use as well and the more I use it the more I understand why so many people like it.

So with all that being said, I’m certain there was still a lot I forgot to mention. I enjoy learning new things everyday and being able to share what I learn with others and it’s my hope that I’ve been able to shed some light on the main differences between MOA and MIL, SFP and FFP and the importance of choosing a scope based on it’s intended purpose.

Id love to start geeking out about my current learning experiences on magnification ranges and how they relate to FOV values, main tube diameters and its effect on light transmission and turret adjustment ranges, eye relief, exit pupil and light transmission, locking turrets, resettable zeros and zero stops, achromatic lenses and chromatic aberration, glass quality, glass polishing and chemical lens coatings etc., but we’ll need to leave that for another time. Until then shoot often and remember - Aim small…miss small!

-Robert Hales
 
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Great write up and explanation. For me, as a field target hunter class shooter, I can't see an advantage for either. I base it on which has the best, for me, reticle for hold over. When I shot WFTF class field target. I used a 10-50x60 scope, which allowed clicking or dialing elevation, never saw that mil or moa had an advantage. This is just my humble opinion. Don
 
The most common questions I get asked by friends looking to purchase a new rifle scope is what is the difference between MOA and MIL, second focal plane and first focal plane reticles, which would I recommend and why. For the longest time my answer to them has been relatively simple and vague to say the least. If you are more familiar with the imperial system and inches then go with MOA. If you are more familiar with the metric 1/10 based system then opt for MIL. As for SFP and FFP reticles, choose SFP if you want a reticle that doesn’t change size as you adjust magnification and FFP if you want a reticle who’s sub-tensions are true to scale no matter what magnification you are on.

Now personally speaking, I have always been an MOA guy myself because I grew up in a country where everything is based on the imperial system and therefore I am more comfortable dealing in inches and fractions of an inch as opposed to the 1/10 scale based metric units. Over the years however, I couldn’t help but notice that a lot of long range and tactical shooters here in the USA seem to prefer the MIL scopes despite the fact that we all use the imperial system. This has always puzzled me and I’ve always wondered what it was that I was missing.

So before I get into what I discovered in my quest to understand what made MIL scopes so popular among shooters in certain shooting disciplines let’s first take a look at the basic difference between these two systems of angular measurement. As I mentioned before, one is closely related to inches while the other is based on a metric 1/10 scale factor.

A minute is just a fancy word for one-sixtieth (think about 60 minutes in an hour). Well, that's the same as saying one minute is a sixtieth of an hour. This minute is gonna be the sixtieth of the angle that is on the circle of 360 degrees. So, the sixtieth of one of those degrees is one minute of angle. It ends up being about 1.0400 inches at 100 yards. Keep in mind that it’s not a size at a certain distance, but rather it's an angle that we're making in the scope that ends up translating to a certain size at a certain distance.

With minute of angle (or MOA for short), one click on your turret is approximately equal to 1/4 MOA or a 1/4” shift of your reticle @ 100 yds. on most scopes and sometimes as low as 1/8 MOA on others. This has always made it easy for me to make calculates in my mind because I’m very familiar with inches.

MILs, like MOA, is also an angular measurement and the length it represents also increases proportionally with distance. For example, 1 mil at 100 yards equals 10cm or 3.6” and 20cm or 7.2” at 200 yards.
Now before we go any further let’s take a look at some rough numbers to put things into perspective.

1 MOA = 1” @ 100 yds & 1 click = .25 “ shift

1 MIL = 3.6” @ 100 yds & 1 click = .36” shift

From this we can see that a MOA scope will allow you to make slightly finer adjustments especially if your scope has 1/8 MOA adjustments which would translate to 1-click moving your reticles roughly only .125”!! This is useful for those who are trying to fine tune their reticle for extremely high level precision shots on small targets such as when shooting bench rest and extreme bench rest matches where you are aiming for a 1/4” X-ring @ up to 100 yds. away! Also, what’s important to note is that in this type of shooting, second focal plane (SFP) reticles are normally preferred because you can turn up the magnification on your scope to zoom in on your target and the size of your reticle remains the same as opposed to first focal plane (FFP) reticles that grow and get get thicker as your magnification increases thereby covering up more of your target. Usually thin reticles are preferred as well as they cover up less of that 1/4” X-ring when zoomed in at 100 yds! My scope of choice for bench rest and extreme bench rest is a Delta Optical Stryker HD 5-50x56 in MOA with a SFP reticle. The floating center dot is so small that I can still see the entire 10 ring at 100 yds on 40x magnification and at 40x my reticle sub-tensions are true to scale. It also has an illuminated center dot for those rare instances when I may be shooting against dark background that makes it difficult to see my reticle.

Now getting back to the topic at hand, I recently started to venture into the world of precision rifle shooting with high power airguns. With the accelerated growth and technological advancements in the airgun industry we are now able to combine the power and efficiency of modern airguns with the increased ballistic performance of airgun specific slugs. This combination now allows airgunners to push the boundaries of what is possible with an airgun. Basically we can now shoot targets much farther away with much more accuracy and precision than was ever possible with traditional drag stabilized diabolo pellets. This has ushered in a new era for airgunners with organizations such as PRS and NRL opening the doors to airguns to compete against rimfire rifles at distances previously unimaginable.

So what does all this have to do with the topic at hand you say?? Well, it’s pretty simple actually. I was looking at a typical NRL event the other day and at the stages and course of fire for each stage and while doing so I was asking myself what characteristics I would want in a scope for this type of shooting. While making a checklist of what I wanted, It quickly became apparent that what I was missing all along was the fact that different scopes are designed for different applications and the decision on which type of scope to buy had less to do with it being “imperial or metric” but more so on the characteristics and feature set of the scope and how well that feature set aligns with what you need it to do for you as a shooter.

So let’s take a look at PRS and NRL shooting for example. In these types of events you are engaging multiple targets of different sizes and different distances all while on the clock. As you move down the course of fire you are engaging targets further and further away and therefore you are constantly dialing for elevation and windage. Since you are on the clock time is of essence so the less time you spend dialing the better right? Here is where the MIL scopes shine. It’s a lot quicker to dial 2 MILS than it is to dial 7 MOA so that’s time saved every time you have to adjust for elevation and windage. The finer adjustments of MOA are no longer of great importance as the sizes of the targets are much larger and that extra level of precision in reticle adjustments is no longer necessary. The targets are not 1/4” at 100 yds anymore either so having a thin reticle that doesn’t get thicker with increased magnification is no longer a priority. Instead, the ability to have your reticle sub-tensions remain true to value at any magnification you may be in is now basically a must have especially in stages where you have to use your reticle to range your targets. So as you can see, the feature set of a scope geared towards one particular style of shooting or application may be significantly different to one designed for another style of shooting or application. Different tools for different jobs… Now when someone asks me what scope I would recommend, my answer is “it depends….”.

My current PRS gun is now topped with a ValdadaOptics Recon G2 4.8-30x56 in MIL (who would have thought??) with a FFP reticle and a 40 mm main tube allowing an elevation adjustment range of 43 MILS or 150 MOA. Plenty for shooting airgun slugs out past 300 yds. So I now have both MOA and MIL scopes with both SFP and FFP reticles. The 1/10 scale is actually pretty simple to use as well and the more I use it the more I understand why so many people like it.

So with all that being said, I’m certain there was still a lot I forgot to mention. I enjoy learning new things everyday and being able to share what I learn with others and it’s my hope that I’ve been able to shed some light on the main differences between MOA and MIL, SFP and FFP and the importance of choosing a scope based on it’s intended purpose.

Id love to start geeking out about my current learning experiences on magnification ranges and how they relate to FOV values, main tube diameters and its effect on light transmission and turret adjustment ranges, eye relief, exit pupil and light transmission, locking turrets, resettable zeros and zero stops, achromatic lenses and chromatic aberration, glass quality, glass polishing and chemical lens coatings etc., but we’ll need to leave that for another time. Until then shoot often and remember - Aim small…miss small!

-Robert Hales
Great explanation, Robert. You touched on so much info. I shoot either MOA or MIL scopes. FFP or SFP. In reality it is whatever type you are most familiar with and what disciplines you participate in. Thank you for taking the time to put all the wonderful info of your article together. The longer one is in this game the more technical you see it. Here's to continued improved accuracy!!
 
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Great explanation, Robert. You touched on so much info. I shoot either MOA or MIL scopes. FFP or SFP. In reality it is whatever type you are most familiar with and what disciplines you participate in. Thank you for taking the time to put all the wonderful info of your article together. The longer one is in this game the more technical you see it. Here's to continued improved accuracy!!
MIL is not metric, it is based on Radians, arc length.
Great explanation, Robert. You touched on so much info. I shoot either MOA or MIL scopes. FFP or SFP. In reality it is whatever type you are most familiar with and what disciplines you participate in. Thank you for taking the time to put all the wonderful info of your article together. The longer one is in this game the more technical you see it. Here's to continued improved accuracy!!
Thanks Linda. Hope all is well with you and Jerry.
 
@RobHales, good post. I would always purchase MOA, was vaguely aware of the differences from MIL. But not in actual shooting. Through the use of an MIL 3-12x44 SF IR FFP. Discovered and continue to confirm through lots of shooting in the wind. That my “windage” hold offs ”are” much less with MIL than with MOA, particularly as the distance increases. I shoot from 25 to 102 yards in my backyard, the hits I get in the wind? MIL for me going forward.
 
The most common questions I get asked by friends looking to purchase a new rifle scope is what is the difference between MOA and MIL, second focal plane and first focal plane reticles, which would I recommend and why. For the longest time my answer to them has been relatively simple and vague to say the least. If you are more familiar with the imperial system and inches then go with MOA. If you are more familiar with the metric 1/10 based system then opt for MIL. As for SFP and FFP reticles, choose SFP if you want a reticle that doesn’t change size as you adjust magnification and FFP if you want a reticle who’s sub-tensions are true to scale no matter what magnification you are on.

Now personally speaking, I have always been an MOA guy myself because I grew up in a country where everything is based on the imperial system and therefore I am more comfortable dealing in inches and fractions of an inch as opposed to the 1/10 scale based metric units. Over the years however, I couldn’t help but notice that a lot of long range and tactical shooters here in the USA seem to prefer the MIL scopes despite the fact that we all use the imperial system. This has always puzzled me and I’ve always wondered what it was that I was missing.

So before I get into what I discovered in my quest to understand what made MIL scopes so popular among shooters in certain shooting disciplines let’s first take a look at the basic difference between these two systems of angular measurement. As I mentioned before, one is closely related to inches while the other is based on a metric 1/10 scale factor.

A minute is just a fancy word for one-sixtieth (think about 60 minutes in an hour). Well, that's the same as saying one minute is a sixtieth of an hour. This minute is gonna be the sixtieth of the angle that is on the circle of 360 degrees. So, the sixtieth of one of those degrees is one minute of angle. It ends up being about 1.0400 inches at 100 yards. Keep in mind that it’s not a size at a certain distance, but rather it's an angle that we're making in the scope that ends up translating to a certain size at a certain distance.

With minute of angle (or MOA for short), one click on your turret is approximately equal to 1/4 MOA or a 1/4” shift of your reticle @ 100 yds. on most scopes and sometimes as low as 1/8 MOA on others. This has always made it easy for me to make calculates in my mind because I’m very familiar with inches.

MILs, like MOA, is also an angular measurement and the length it represents also increases proportionally with distance. For example, 1 mil at 100 yards equals 10cm or 3.6” and 20cm or 7.2” at 200 yards.
Now before we go any further let’s take a look at some rough numbers to put things into perspective.

1 MOA = 1” @ 100 yds & 1 click = .25 “ shift

1 MIL = 3.6” @ 100 yds & 1 click = .36” shift

From this we can see that a MOA scope will allow you to make slightly finer adjustments especially if your scope has 1/8 MOA adjustments which would translate to 1-click moving your reticles roughly only .125”!! This is useful for those who are trying to fine tune their reticle for extremely high level precision shots on small targets such as when shooting bench rest and extreme bench rest matches where you are aiming for a 1/4” X-ring @ up to 100 yds. away! Also, what’s important to note is that in this type of shooting, second focal plane (SFP) reticles are normally preferred because you can turn up the magnification on your scope to zoom in on your target and the size of your reticle remains the same as opposed to first focal plane (FFP) reticles that grow and get get thicker as your magnification increases thereby covering up more of your target. Usually thin reticles are preferred as well as they cover up less of that 1/4” X-ring when zoomed in at 100 yds! My scope of choice for bench rest and extreme bench rest is a Delta Optical Stryker HD 5-50x56 in MOA with a SFP reticle. The floating center dot is so small that I can still see the entire 10 ring at 100 yds on 40x magnification and at 40x my reticle sub-tensions are true to scale. It also has an illuminated center dot for those rare instances when I may be shooting against dark background that makes it difficult to see my reticle.

Now getting back to the topic at hand, I recently started to venture into the world of precision rifle shooting with high power airguns. With the accelerated growth and technological advancements in the airgun industry we are now able to combine the power and efficiency of modern airguns with the increased ballistic performance of airgun specific slugs. This combination now allows airgunners to push the boundaries of what is possible with an airgun. Basically we can now shoot targets much farther away with much more accuracy and precision than was ever possible with traditional drag stabilized diabolo pellets. This has ushered in a new era for airgunners with organizations such as PRS and NRL opening the doors to airguns to compete against rimfire rifles at distances previously unimaginable.

So what does all this have to do with the topic at hand you say?? Well, it’s pretty simple actually. I was looking at a typical NRL event the other day and at the stages and course of fire for each stage and while doing so I was asking myself what characteristics I would want in a scope for this type of shooting. While making a checklist of what I wanted, It quickly became apparent that what I was missing all along was the fact that different scopes are designed for different applications and the decision on which type of scope to buy had less to do with it being “imperial or metric” but more so on the characteristics and feature set of the scope and how well that feature set aligns with what you need it to do for you as a shooter.

So let’s take a look at PRS and NRL shooting for example. In these types of events you are engaging multiple targets of different sizes and different distances all while on the clock. As you move down the course of fire you are engaging targets further and further away and therefore you are constantly dialing for elevation and windage. Since you are on the clock time is of essence so the less time you spend dialing the better right? Here is where the MIL scopes shine. It’s a lot quicker to dial 2 MILS than it is to dial 7 MOA so that’s time saved every time you have to adjust for elevation and windage. The finer adjustments of MOA are no longer of great importance as the sizes of the targets are much larger and that extra level of precision in reticle adjustments is no longer necessary. The targets are not 1/4” at 100 yds anymore either so having a thin reticle that doesn’t get thicker with increased magnification is no longer a priority. Instead, the ability to have your reticle sub-tensions remain true to value at any magnification you may be in is now basically a must have especially in stages where you have to use your reticle to range your targets. So as you can see, the feature set of a scope geared towards one particular style of shooting or application may be significantly different to one designed for another style of shooting or application. Different tools for different jobs… Now when someone asks me what scope I would recommend, my answer is “it depends….”.

My current PRS gun is now topped with a ValdadaOptics Recon G2 4.8-30x56 in MIL (who would have thought??) with a FFP reticle and a 40 mm main tube allowing an elevation adjustment range of 43 MILS or 150 MOA. Plenty for shooting airgun slugs out past 300 yds. So I now have both MOA and MIL scopes with both SFP and FFP reticles. The 1/10 scale is actually pretty simple to use as well and the more I use it the more I understand why so many people like it.

So with all that being said, I’m certain there was still a lot I forgot to mention. I enjoy learning new things everyday and being able to share what I learn with others and it’s my hope that I’ve been able to shed some light on the main differences between MOA and MIL, SFP and FFP and the importance of choosing a scope based on it’s intended purpose.

Id love to start geeking out about my current learning experiences on magnification ranges and how they relate to FOV values, main tube diameters and its effect on light transmission and turret adjustment ranges, eye relief, exit pupil and light transmission, locking turrets, resettable zeros and zero stops, achromatic lenses and chromatic aberration, glass quality, glass polishing and chemical lens coatings etc., but we’ll need to leave that for another time. Until then shoot often and remember - Aim small…miss small!

-Robert Hales


One MOA Calculation

How to determine one MOA for any target. Note, MOA = minute of angle.

  • Calculate the distance to the target.
  • Convert this number to inches or centimeters for metric.
  • Double this number, (Diameter of a circle).
  • Use Pi, 3.14159 times the number in step 3, (Circumference of a circle is Pi x D).
  • Divide this number by 21,600, (Note 21,600 = minutes in a circle, 360 degrees x 60 minutes in one degree).
This number is the one MOA in inches, or centimeters if used, for this target at the calculated distance or range. Group shots measured center to center.

Example:

  • 100 yards to target.
  • 100 x 3’ x 12” = 3600” to target.
  • 3600” x 2 = 7200”, (Diameter of 100 yard circle in inches).
  • Pi 3.14159 x 7200” = 22,619.448”, (Circumference of 100 yard circle).
  • 22,619.448”/21,600 = 1.04719”, (One MOA at 100 yards in inches).
This number is usually rounded to 1” for the one MOA at 100 yards.

The one MOA = 1” is an ARC measurement and not a straight line as it is a very small section, 1” of the overall circle circumference at 100 yards.

A trivia note – one MOA on the moon is about 69.5 miles, 111.85 Kilometers! (238,900 miles, 384,472.28 Kilometers to the moon).
 
The most common questions I get asked by friends looking to purchase a new rifle scope is what is the difference between MOA and MIL, second focal plane and first focal plane reticles, which would I recommend and why. For the longest time my answer to them has been relatively simple and vague to say the least. If you are more familiar with the imperial system and inches then go with MOA. If you are more familiar with the metric 1/10 based system then opt for MIL. As for SFP and FFP reticles, choose SFP if you want a reticle that doesn’t change size as you adjust magnification and FFP if you want a reticle who’s sub-tensions are true to scale no matter what magnification you are on.

Now personally speaking, I have always been an MOA guy myself because I grew up in a country where everything is based on the imperial system and therefore I am more comfortable dealing in inches and fractions of an inch as opposed to the 1/10 scale of the metric system. Over the years however, I couldn’t help but notice that a lot of long range and tactical shooters here in the USA seem to prefer the MIL scopes despite the fact that we all use the imperial system. This has always puzzled me and I’ve always wondered what it was that I was missing.

So before I get into what I discovered in my quest to understand what made MIL scopes so popular among shooters in certain shooting disciplines let’s first take a look at the basic difference between these two systems of angular measurement. As I mentioned before, one is closely related to inches while the other is based on a 1/10 scale factor like the metric system. For example 1MOA is approximately 1” at 100 yds and 1MIL is 10cm at 100 meters. You get my point.

A minute is just a fancy word for one-sixtieth (think about 60 minutes in an hour). Well, that's the same as saying one minute is a sixtieth of an hour. This minute is gonna be the sixtieth of the angle that is on the circle of 360 degrees. So, the sixtieth of one of those degrees is one minute of angle. It ends up being about 1.0400 inches at 100 yards. Keep in mind that it’s not a size at a certain distance, but rather it's an angle that we're making in the scope that ends up translating to a certain size at a certain distance.

With minute of angle (or MOA for short), one click on your turret is approximately equal to 1/4 MOA or a 1/4” shift of your reticle @ 100 yds. on most scopes and sometimes as low as 1/8 MOA on others. This has always made it easy for me to make calculates in my mind because I’m very familiar with inches.

MILs, like MOA, is also an angular measurement and the length it represents also increases proportionally with distance. For example, 1 mil at 100 meters equals 10cm or 3.6” at 100 yds and 20cm at 200 meters or 7.2” at 200 yards.
Now before we go any further let’s take a look at some rough numbers to put things into perspective. For comparison purposes we will convert both MOA and MILS to inches and although 1MOA = 1.047”, we’ll round that down to 1” to for simplicity purposes.

1 MOA = 1” @ 100 yds & 1 click = .25 “ shift

1 MIL = 3.6” @ 100 yds & 1 click = .36” shift

From this we can see that a MOA scope will allow you to make slightly finer adjustments especially if your scope has 1/8 MOA adjustments which would translate to 1-click moving your reticles roughly only .125”!! This is useful for those who are trying to fine tune their reticle for extremely high level precision shots on small targets such as when shooting bench rest and extreme bench rest matches where you are aiming for a 1/4” X-ring @ up to 100 yds. away! Also, what’s important to note is that in this type of shooting, second focal plane (SFP) reticles are normally preferred because you can turn up the magnification on your scope to zoom in on your target and the size of your reticle remains the same as opposed to first focal plane (FFP) reticles that grow and get get thicker as your magnification increases thereby covering up more of your target. Usually thin reticles are preferred as well as they cover up less of that 1/4” X-ring when zoomed in at 100 yds! My scope of choice for bench rest and extreme bench rest is a Delta Optical Stryker HD 5-50x56 in MOA with a SFP reticle. The floating center dot is so small that I can still see the entire 10 ring at 100 yds on 40x magnification and at 40x my reticle sub-tensions are true to scale. It also has an illuminated center dot for those rare instances when I may be shooting against dark background that makes it difficult to see my reticle.

Now getting back to the topic at hand, I recently started to venture into the world of precision rifle shooting with high power airguns. With the accelerated growth and technological advancements in the airgun industry we are now able to combine the power and efficiency of modern airguns with the increased ballistic performance of airgun specific slugs. This combination now allows airgunners to push the boundaries of what is possible with an airgun. Basically we can now shoot targets much farther away with much more accuracy and precision than was ever possible with traditional drag stabilized diabolo pellets. This has ushered in a new era for airgunners with organizations such as PRS and NRL opening the doors to airguns to compete against rimfire rifles at distances previously unimaginable.

So what does all this have to do with the topic at hand you say?? Well, it’s pretty simple actually. I was looking at a typical NRL event the other day and at the stages and course of fire for each stage and while doing so I was asking myself what characteristics I would want in a scope for this type of shooting. While making a checklist of what I wanted, It quickly became apparent that what I was missing all along was the fact that different scopes are designed for different applications and the decision on which type of scope to buy had less to do with it being “imperial or metric” but more so on the characteristics and feature set of the scope and how well that feature set aligns with what you need it to do for you as a shooter.

So let’s take a look at PRS and NRL shooting for example. In these types of events you are engaging multiple targets of different sizes and different distances all while on the clock. As you move down the course of fire you are engaging targets further and further away and therefore you are constantly dialing for elevation and windage. Since you are on the clock time is of essence so the less time you spend dialing the better right? Here is where the MIL scopes shine. It’s a lot quicker to dial 2 MILS than it is to dial 7 MOA so that’s time saved every time you have to adjust for elevation and windage. The finer adjustments of MOA are no longer of great importance as the sizes of the targets are much larger and that extra level of precision in reticle adjustments is no longer necessary. The targets are not 1/4” at 100 yds anymore either so having a thin reticle that doesn’t get thicker with increased magnification is no longer a priority. Instead, the ability to have your reticle sub-tensions remain true to value at any magnification you may be in is now basically a must have especially in stages where you have to use your reticle to range your targets. So as you can see, the feature set of a scope geared towards one particular style of shooting or application may be significantly different to one designed for another style of shooting or application. Different tools for different jobs… Now when someone asks me what scope I would recommend, my answer is “it depends….”.

My current PRS gun is now topped with a ValdadaOptics Recon G2 4.8-30x56 in MIL (who would have thought??) with a FFP reticle and a 40 mm main tube allowing an elevation adjustment range of 43 MILS or 150 MOA. Plenty for shooting airgun slugs out past 300 yds. So I now have both MOA and MIL scopes with both SFP and FFP reticles. The 1/10 scale is actually pretty simple to use as well and the more I use it the more I understand why so many people like it.

So with all that being said, I’m certain there was still a lot I forgot to mention. I enjoy learning new things everyday and being able to share what I learn with others and it’s my hope that I’ve been able to shed some light on the main differences between MOA and MIL, SFP and FFP and the importance of choosing a scope based on it’s intended purpose.

Id love to start geeking out about my current learning experiences on magnification ranges and how they relate to FOV values, main tube diameters and its effect on light transmission and turret adjustment ranges, eye relief, exit pupil and light transmission, locking turrets, resettable zeros and zero stops, achromatic lenses and chromatic aberration, glass quality, glass polishing and chemical lens coatings etc., but we’ll need to leave that for another time. Until then shoot often and remember - Aim small…miss small!

-Robert Hales
Milliradians, (MRAD or Mil) and Minute of Angle, (MOA) Trivia

(Best with a 6 pack of BUD or when you have absolutely nothing to do!)

Formula for the circumference of a circle = Diameter, (D) x Pi, (Pi = 3.14159.)

There are 7200” in (D) diameter of a 100 yard circle. (100 x 36” x 2 = 7200”)

Circumference of a circle at 100 yards = 22,619.448”, (7200” x 3.14159 Pi.)

MRAD or MIL and MOA is an angular, curved, measurement at a specific distance or range from the center of the circle. (A small piece or section of the circumference.)

6,283.185 Milliradians (MRAD) = 1 CIRCLE, (Pi 3.14159 x 2 x 1000 = 6,283.185 mathematical, 17.45 milliradians per degree.)

6,400 Milliradians = 1 CIRCLE, (NATO rounded MRAD.)

21,600 Minutes = 1 CIRCLE, (360 degrees x 60 Minutes in 1 degree = 21,600 minutes)

1 MOA = 1.0471975” at 100 yards, 22,619.448”/21,600 Minutes, (1” rounded.)

1 MRAD = 3.6” at 100 yards, 22,619.448”/6283.185 MRAD, (mathematical.)

1 NATO MRAD = 3.534” at 100 yards, 22,619.448/6400 MRAD.

1 MRAD = 10 cm at 100 meters. (2 x PI x 1000 = 6283.185 MRADs in a circle). 100 meters = 10,000 cm x 2 = 20,000 cm in diameter of 100 meter circle. 20K x PI = 62,831.85/6,283.18 MRADs = 10 cm.

1 MRAD at 100 meters = 10 centimeters.

1 MOA at 200 yards = 2”, at 400 yards = 4”, at 800 yards = 8”, etc.

1 MOA at 50 yards = ½”, 1 MOA at 25 yards = ¼”.

1 MOA at 1 mile = 18.43”

1 MOA on the Moon = 69.5 miles. (238,900 miles to the Moon)

Scope settings MOA or MRAD.

It also depends on what your scope's notion of 1 milliradian is, because the NATO milliradian differs from the mathematical definition of a milliradian.

A mathematically accurate radian is that part of a circle where 2 * PI radians is a full circle, and a milliradian, (MRAD), is 1/1000th of a radian, so a full circle is equal to approximately 6283.185 milliradians (2000 * PI).

But the NATO definition of a milliradian for use in ballistics is that a full circle is split into 6400 NATO milliradians.

Anyway, the difference is not very large, with mathematically accurate MRADs, 1 MRAD is 100 cm @ 1000 m, with 1 NATO MRAD, it is 98.2 cm @ 1000 m. For this reason, if your scope uses mathematically accurate MRADs, 1 MRAD is about 3.44 MOAs, but if it uses NATO MRADs, then 1 MRAD is 3.375 MOAs.

The distance of the reticle's movement per click is tan(angle) * distance, however, at longer distances this is not exactly equal to the change in point of impact, because of the difference between changes to the line of sight and changes in the bullet's trajectory.

degrees = MOAs / 60
MOAs = degrees * 60

degrees = MRADs / (PI * 1000) * 180
degrees = (MRADs / 6400) * 360 [with NATO MRADs]
MRADs = (degrees / 180) * PI * 1000
MRADs = (degrees / 360) * 6400 [with NATO MRADs]

MOAs = MRADs / (PI * 1000) * 10800
MOAs = (MRADs / 6400) * 21600 [with NATO MRADs]
MRADs = (MOAs / 10800) * PI * 1000
MRADs = (MOAs / 21600) * 6400 [with NATO MRADs]
 
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Great write up and explanation. For me, as a field target hunter class shooter, I can't see an advantage for either. I base it on which has the best, for me, reticle for hold over. When I shot WFTF class field target. I used a 10-50x60 scope, which allowed clicking or dialing elevation, never saw that mil or moa had an advantage. This is just my humble opinion. Don
Absolutely! Like I said, you choice needs to be founded on what is important to you and what specifically you are looking for in a scope. In your particular situation the reticle was the deciding factor. Thanks for sharing your perspective. Much appreciated. 👍
 
Great explanation, Robert. You touched on so much info. I shoot either MOA or MIL scopes. FFP or SFP. In reality it is whatever type you are most familiar with and what disciplines you participate in. Thank you for taking the time to put all the wonderful info of your article together. The longer one is in this game the more technical you see it. Here's to continued improved accuracy!!
Thank you Linda!
 
MIL is not metric, it is based on Radians, arc length.
You are absolutely correct. It’s not metric per se but is based on a 1/10 scale similar to the metric system and therefore easily identifiable with metric units like mm, cm, meter, km etc… hence 1MIL is usually identified as 10cm at 100 meters and one click is 1cm at 100 meters. Thanks for your input. 👍
 
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@RobHales, good post. I would always purchase MOA, was vaguely aware of the differences from MIL. But not in actual shooting. Through the use of an MIL 3-12x44 SF IR FFP. Discovered and continue to confirm through lots of shooting in the wind. That my “windage” hold offs ”are” much less with MIL than with MOA, particularly as the distance increases. I shoot from 25 to 102 yards in my backyard, the hits I get in the wind? MIL for me going forward.
Funny you should say that. I have a friend that put a MIL scope on his squirrel gun and he said pretty much the same thing to me that you just said. Whatever works best right? Thanks for sharing your experience. 👍
 
@RobHales, the horizontal hash marks on my scope below the center dot are: .25 MIL, .5 MIL, 1 MIL, 2 MIL long. For hitting black walnut husks, wine corks, chalk, etc. at 50 yards. I use 2 MILs of hold over, which is a .5 MILs long, hash mark. Depending on which way the wind is blowing if I hold off at either end of said hash mark, keeping the tip on the target? That’s already .9“ of hold off. At 100 yards, the 1 MIL long hash mark, gives 1.80” of hold off without taking reticle of target. Was just outside using the falling snow as a wind indicator and hitting those walnut husk at 50. I do shoot, almost everyday.
 
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@RobHales, the horizontal hash marks on my scope below the center dot are: .25 MIL, .5 MIL, 1 MIL, 2 MIL long. For hitting black walnut husks, wine corks, chalk, etc. at 50 yards. I use 2 MILs of hold over, which is a .5 MILs long, hash mark. Depending on which way the wind is blowing if I hold off at either end of said hash mark, keeping the tip on the target? That’s already .9“ of hold off. At 100 yards, the 1 MIL long hash mark, gives 1.80” of hold off without taking reticle of target. Was just outside using the falling snow as a wind indicator and hitting those walnut husk at 50. I do shoot, almost everyday.
Sweet!!
 
Ahhhhh…MIL vs MOA. Blonde vs Brunette (Blonde). Scotch vs Bourbon (Bourbon). Jack vs Tiger (Hogan). I wonder how much oxygen has been wasted on the MIL vs MOA argument through the years? Not to mention the amount of beer that has been consumed while doing so!

Bottom line? Whatever works best for you! To me, I don’t see any inherent advantage or disadvantage to either method. Some would tout the MIL systems ability to determine ranges as making it superior. Well, you can do the same thing with MOA, it’s just a different formula. And besides, unless they’re prohibited for your particular competition of choice, we’ll all likely be reaching for our laser range finders!

And I don’t see how using the MIL system is appreciably faster than MOA. In Rob’s scenario, he moves his MIL scope turret from 0 to 2. I move my MOA scope turret from 0 to 7. 20 clicks vs 28 clicks…both just a bit over a quarter turn on the turret. You’re moving the crosshairs the same distance, just in different increments. Now…if I could think in MIL/Metric, I’d probably agree with Rob!

And I absolutely agree with Rob that MIL/MRAD is metric…despite it technically not being metric. One MIL equals 10cm at 100 meters? One click on a MIL scope is 1cm? That’s metric enough for me!

I genuinely believe much of the MIL’s popularity stems from somes infatuation with all things “tactical” and “sniperesque”. If you were to go to some of these “sniper” websites and proclaim MOA was just as effective or efficient as MIL, you would likely be eviscerated by some keyboard warrior, replete with a battle beard, sitting behind his computer in mom and dad’s basement (for the record, I was a “sniper” on a SWAT team, attended sniper schools, taught at sniper schools, deployed with a rifle, blah, blah, blah…).

I did not know that there was two MRAD’s, much like there are two MOA’s. A “real” one, and the NATO version. I’ve always described the two MOA’s as the “real” MOA (1.047 at 100 yards), and “layman’s” MOA (1 inch at 100 yards).

It’s all about what works for you! MOA makes sense to me as I’ve been reading Imperial tape measures and micrometers for too long to think in a different unit of measurement. If MIL works for you, rock on!

Cool thread with some interesting stuff within. Thanks to Rob for starting it!

Justin