MIL vs MOA! Lets get right into this. When discussing MIL vs MOA we should begin by describing each and how they work, as well as the similarities between them. MILS is the plural form of MIL which is short for Milliradian. A Milliradian is 1/1000th of a Radian. This is a way of measuring a circle. How does that apply to the MILS vs MOA discussion? Well, at 100 yards the size of a MIL is 3.6 inches. Why? Simple, because a Milliradian is always 1/1000th of a Radian. Clear as mud right? Look at it this way, the total distance is your Radian. So if 100 yards is my radian, than a MIL at 100 yards will be 1/1000th of the total. There are 3600 inches in 100 yards, so a MIL will subtend to 3.6 inches at 100 yards.
MILS vs MOA Examples
Lets do another example for the MIL vs MOA discussion. The 1000 Yard line, if that is our radian, then the size of the MIL will be exactly 1/1000th of the total distance. If there are 3600 inches in 100 yards, there are 36,000 inches in 1000 yards, right? Divide the 36,000 by 1000 yards and you get 36 inches. That is the size of a MIL at 1000 yards. This seems complicated but in practice it becomes much simpler because we abandon the conversion. I’m explaining the math to give you a foundation. In practice you don’t relate distances or corrections to firing solutions in inches. You relate them in MILS so you can abandon the conversion. Here’s what I mean.
Rather than say, “You missed the target by 36 inches at 500 yards,” you relate the offset based off the reticle the shooter is using. Since he bought a proper scope that has adjustments in increments of a MIL and a reticle based on MILS for scale, you tell him he needs to hold 2 MILs to the left and 2 MILs high. He uses the reticle to adjust for his next shot. You don’t do any of the conversion math. That’s for later and only if you want to. Everybody will be working off the MIL scale so there’s no need to relate distance in inches. The MIL vs MOA debate really has more to do with executing either system properly than which is better.
Minutes of Angle work the same way, but the math is a little different. A Minute of Angle also refers to measuring a circle. There are 360 degrees in a circle and 60 minutes per degree. Thus there are 21600 minutes in a circle. To calculate the circumference of a circle, you have to multiply the diameter against pi for the value. So if our distance to target is 100 yards that is the radius of the circle. Multiply that distance by two for the diameter of 200 yards. 200 yards x Pi would give you a value of 628.32 yards. 36 inches per yard multiplied by 628.32 would give you 22619.32 inches. If you divide our 22619 inches by 21600 minutes you get 1.047 inches. That is the commonly accepted value of one MOA at 100 yards. In practice. the .047 is dropped and people say that 1 MOA at 100 yards is 1 inch. 1 MOA at 200 yards is 2 inches, etc.
Again, I’m explaining the conversions involved in the MIL vs MOA debate so that the origin of the numbers we use in practice is known and makes sense. In practice though, you don’t do any of this conversion math today. The reason the conversions are around is because precision rifle scopes used to be commonly found with mismatched reticles and turrets. The Reticle might be a MIL based reticle like a military Mil Dot reticle, but the turrets adjust the reticle in 1/4 MOA increments. I’m sure you can already see why that could be really confusing.
If I miss by a full MIL in my scope at 1000 yards, then I have to do math to dial a correction. 1 Mil at 1000 yards is 36 inches, so I need to dial 3.l6 minutes of correction, but I have to multiply that by four for the actual number of 1/4 MOA clicks to adjust my scope and I get 14.4 clicks. This is what I mean by proper execution of either system when discussing MIL vs MOA. If the reticle and turrets match then the rest of the process is easily ten times easier.
MILS vs MOA Keep It Simple
You can sit there and do all the math or you could save yourself a ridiculous amount of energy and frustration and make sure your reticle matches your turrets!!! If your reticle and turrets match, all the conversions are pointless and you don’t need to use them. If you look through your scope and you note that your miss is a half MIL to the left, you can just dial 0.5 MILS of windage correction or hold a half MIL to the left with the reticle. You don’t need to convert anything. What you see in the reticle is what you get with the turrets. This works for MOA or MIL based scopes. If you are off by 3 MOA on the scope, you can dial or hold 3 MOA worth of correction to get on target.
Have a healthy understanding of both systems. MOA was dominant for a long time. So target size is often expressed in Minutes of Angle. If somebody tells me the target at 500 yards is 2 MOA in size I know I’m shooting at a roughly 10 inch target. The accuracy potential of a rifle is often expressed in Minutes of Angle. Somebody might tell you their custom precision rifle is a ‘half minute gun.” What he’s saying is that it will produce a group of roughly 0.5 inches at 100 yards, 2.5 inches at 500 yards, and so on and so forth. Those sort of things are not expressed in MILS. However, MIL based scopes are becoming extremely popular.
Every time the MIL vs MOA debate comes up, somebody asks which system is better? It’s really a personal preference. MILS is pretty popular these days so if you don’t have either, that would be my recommendation just so you are speaking the same lingo as the majority of shooters these days. If you already spent good money on a MOA based scope before you got into precision rifle shooting it will work just fine provided that the reticle and turrets match. Keep things simple whenever possible. All my scopes, my spotting scope, my monocular, my laser range finder, all use MIL based reticles. The conversion isn’t terrible, but keep things simple where you can, your blood pressure will thank you for it.