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
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
