This debate is never going to end, but we should agree on the facts. Every day we see the uninformed arguments how one angular unit of measurement is better than the other. The truth of the matter is, one is not better, they are just different ways of breaking down the same thing.
Personally, outside of the disciplines like Benchrest Shooting and F Class, I think Minutes of Angle should be retired. We have bastardized the unit to the point people have no idea a true MOA is not 1″ at 100 yards, or 10″ at 1000, but 1.047″ and 10.47″ at 1000. If you round this angle, you create errors at the longer distances. We shoot at longer ranges, 5% is a lot more than you think.
Shooter MOA or Inch Per Hundred Yard (IPHY)
Shooter MOA or IPHY is not True MOA, and yes it does matter when companies mix them. Having someone question how IPHY is different when they don’t understand we don’t use 1 MOA or even 10 MOA to hit a 1000 yard target. If we consider a 308 as a point of reference, we are looking at almost 20″ of variation. Or 38.3 MOA vs 40.1 IPHY, that is 17″ of variation at 1000 yards. You see we dial more than 10, we dial close to 40, you have to compound those errors the farther out you go.
We can quickly point to the adoption of Mils here with the Military to demonstrate the ease of use, but then the Americans reading this will argue inches as if Mils only work with the metric system. Mils are base 10 and unfortunately Mr & Mrs. America thinking in fractions is nowhere as simple as sliding the decimal point.
Mils work with Inches and Yards
3600 inches is 100 yards, 1/1000 of that is 3.6″ and adjusting in .1 mils means we moved the bullet .36″ per click at 100. See what we did there, we moved the decimal point using Inches and Yards.
While Milliradians were added to the metric system many years ago, it was never designed to be a metric unit and works outside the metric system as this is an angle. Every angle has a linear distance between it. You should be ignoring this and using the angle vs. picking a linear value to adjust your correction.
The fact the bullet hit 12.8″ away from center is meaningless. You would also need to know the range in order to convert the correction back to your scope. But I said the bullet hit 1.6 MOA from center you now have an actionable answer. The Mil Guys would simply dial .4 mils to hit the same target.
Minutes of Angle started out like that too, but unfortunately, companies took shortcuts and ruined it for everyone. It was easier to manufacturer 1″ vs. adding in the .047″. Remember long range back in the day was between 400 and 700 yards. Read any old school book on ballistic, and it rarely goes past those ranges in their examples. Today we are shooting beyond 1000 yards so matters more than ever, you have to take it into account.
Defaulting your program to MOA when you are using IPHY is a significant point of error. JBM online is a great place to demonstrate this as you can include both MOA and IPHY in the output.
Remember it’s 36 to 39 MOA to reach 1000 yards. If you think your scope adjusts in MOA and not IPHY, then you dial 36 instead of 39 you just missed. It works both ways, not every MOA scope is TMOA, some are SMOA. The compounding error is across the total adjustment and not just the 1 MOA.
In the video, I demonstrate hitting a standard target with both units of angles. One is not more accurate than the other. I am not a measurable magnitude from the center of the plate. Using JBM the same way we can see that both correctly move us to the target. The difference is less than a bullet width. I have no trouble zeroing or hitting the center of a Shoot N C target keeping me squared away.
Where does this practical exercise come into play?
When shooting with other people or when picking a reticle.
Next to the shooting discipline you choose to engage in, F Class vs. PRS vs. BenchRest vs. 3 Gun, etc. Communication is your number one consideration.
What are your friends and fellow competitors shooting?
You want to be able to communicate and understand what a fellow competitor is talking about when he walks off the line. You can convert using 3.43, by multiplying or dividing the competing unit of adjustment against the other. That will give you a direct conversion.
12 MOA / 3.43 = 3.5 Mils
4.2 Mils x 3.43 = 14.4 MOA
It’s More about the Reticle
Next, you have your reticle choices. You will find more adaptable options when it comes to Mil Based scopes vs. an MOA one. That is changing a minimal amount as manufacturers try to catch up. But a reticle with 1 MOA hash marks is not as fine as a scope with .2 or even .1 lines. You now have to break up an already fine 1 MOA into quarters; vs. already having reticles with .1 mils.
Pick the reticle based on your initial impression as well as your use. You don’t need a Christmas tree reticle to shoot F Class. You are not going to hold on target 8 mils down. By the same token, You don’t want to use a Nightforce FC-3G reticle for PRS matches.
There are a lot of articles about the nuts and bolts of Mils and MOA. You can dig deep or just understand we are using the angle and there is no need to convert to a linear distance. A Mil is a Mil, and a MOA is a MOA (Unless it’s not because you didn’t check)
Match the Reticle to the Turrets for Success
We match our scope reticle to our turret adjustment, so at the end of the day, “What you See is What You Get.” It matches what we see in the reticle so we can dial the correction on the turret. A super simple concept that allows the shooter to use the calibrated ruler 3 inches in front of their nose.
Measure, adjust, repeat
But do your homework, look at the schematics and understand manufacturers do not explain this very well. It’s the shooter’s job to understand. This is key because ballistic software only knows what you tell it. If you confuse the two, the software will not help you.