Mil-dot scopes have been around for a while and are multi-faceted tools that can give you a lot of functionality in one fairly simple layout. Please note that we will be talking strictly about mil-dot reticles in this article. While some mil-dot reticles also come with Christmas trees to make holds easier, the tree is in addition to the mil-dot reticle itself.
We’re starting from the very beginning in this article, so we’ll first need to cover what exactly a “mil” is, along with some other basic information that is crucial to understand well enough that it becomes second nature.
How to Use a Mil-Dot Scope
A standard mil-dot reticle utilizes dots that are .2 mil in diameter, with a one mil gap between dots from center to center. The dots allow you to quickly realign your aiming point based on the distance to the target and the wind factor.
Remember that many scopes advertised as “mil-dot” are not standard; the dots might be larger or smaller in diameter, and in some cheaper scopes, the distance between dots might not even be correct. Test your scope against known distances & sizes before trusting it with something mission-critical.
There’s a lot more that mil-dots can be used for and some important things to understand in order to be able to use a mil-dot reticle properly, so let’s dive right into those.
1. How Distance Is Represented
If you’re brand new to this, you might ask, “What exactly is a mil? Is it like a millimeter?”. The answer is yes and no. Both are units of measurement, but a millimeter is a measurement of distance along a straight line, like a ruler. A mil is a measurement of an angle, so it’s an alternative to “degrees” when measuring angles in a geometric shape.
Things like mils or MOAs are used instead of linear measurements like millimeters or centimeters because it makes it easier to adapt your scope to vastly disparate distances. For example, if you had a reticle with hash marks spaced exactly 10 centimeters apart, that might be really useful at 100 yards but worthless at 1000.
A 1-mil spacing, on the other hand, is useful at both distances. It translates into a much smaller overall distance at 100 yards than it does at 1000 yards.
So, What is a Mil?
A single mil, short for “milliradian,” is about 0.057 degrees. You can also reverse it and say that it takes about 17.5 mils to equal a single degree.
That’s complicated, so instead, just remember that 1 mil is equal to about 3.6 inches of distance at 100 yards. From there, the math is easy: at 200 yards, 1 mil is equal to 7.2 inches. At 1000 yards, it’s 36 inches, etc.
That’s the beauty of mils; they’re applicable at any and every distance.
This comes with a very important caveat: your mil-dot reticle will most likely only be accurate at a specific magnification. There’s really only one exception to this, but for the vast majority of mil-dot scopes out there, you need to know what magnification the reticle was set to be accurate at.
Let me explain: when you zoom in on most scopes (ones that use Second Focal Plane reticles), the reticle does not get bigger, even though the image in your scope does. This means that your mil-dot reticle can only accurately represent 3.6 inches at 100 yards at a single point in the magnification range.
At all other points, 3.6 inches will either appear larger or smaller than the space between the mil-dots.
Many mil-dot reticles have their “true” setting at 10x magnification, regardless of whether that’s the end of the magnification. Any reticle not set to 10x is likely set to the max magnification of the scope.
3. The Case for FFP Mil-Dot Reticles
The exception to the above is when you use a scope with a First Focal Plane reticle. An FFP reticle stays true to size at all magnifications by growing and shrinking as you zoom in and out.
This can be nice when you want to get a little more versatility out of your scope. Knowing that a mil is 3.6 inches at 100 yards is nice and all, but when you have to be at 10x magnification to have accurate mil markings, that’s pretty useless at 100 yards.
The counter-argument to that is this: how often will you really be calculating holdovers at 100 yards?
It’s a fair point regarding elevation, but a strong crosswind can make a difference within 100 yards. Sure, you can always adjust using the turret, and just having dots for reference can help you eyeball the maximum 2-3 inch adjustment even in a 90-degree strong wind. Still, there is certainly an argument to be made that FFP is a simpler solution.
For most shooters, it’s probably not worth paying extra or limiting your selection to just FFP reticles. However, price, reviews, and quality being equal, I would say an FFP reticle has a slight edge over an SFP regarding mil-dots.
You can also use a mil-dot reticle for rangefinding or at least range-estimating. In fact, rangefinding is one of the main reasons the mil-dot reticle was designed. This isn’t a unique trait of mil-dot reticles – lots of other types of reticles can be used in a similar way, but a mil-dot reticle is simple to use for this.
To use a mil-dot reticle for rangefinding, all you need to know is how tall or wide your target is or close to it. For example, the average adult coyote is between 21 and 24 inches tall. So at 100 yards, the average coyote should appear between 6 and 6.5 mils tall.
Therefore, if you’re looking at a coyote through your scope (at the correct magnification) and the coyote only appears 3 mil tall, you can estimate that the coyote is about 200 yards away. If the coyote appears to be about .6 mil tall, you can estimate that the coyote is about 1000 yards away.
Since game will rarely be exactly 200, 300, or some other easy-to-math distance away, you can also memorize the following equation: multiply the size of the target by 27.77, then divide the result by how many mils it appears to be, rounded to the nearest 10th.
Known target size x 27.77/size in mils
We can use the above coyote example to test this out. We know the target should be close to 22 inches tall, so we can pre-multiply 22 by 27.77 and remember that number every time we go coyote hunting. That number is 610.94.
Now, whenever we have a coyote in our scope, we just measure how many mils tall the coyote appears. Let’s say it’s 3.5 mils tall.
Now we just divide 610.94 by 3.5. Doing so, we discover that the coyote is 175 yards away or thereabouts. This isn’t a perfect example because the coyote could be significantly larger or smaller than average, but hopefully, that illustrates the point.
Important Note: to range find with a mil-dot reticle using this calculation, you must know the target’s height in inches.
How to Make Adjustments Using a Mil-Dot Scope
1. Holdovers for Distance/Elevation
Once you wrap your head around all the numbers, calculations, and whatnot from the above section, performing holdovers is easier. Once you know the distance you’re shooting at, either from estimating using your mil-dots or by using a rangefinder, you just hold up or down to wherever you need for your load.
A mil-dot reticle can’t replace a good dope card, though, because you still need to know how far the round you’re shooting will drop at certain distances. Knowing that your target is 300 yards away isn’t enough information to know where to place your aiming point for (for example) a .224 Valkyrie that’s zeroed at 100 yards.
For that, you need to either know your load well enough to do the math mentally or have a dope card that keeps track of everything for you. You can also just pre-math the holds into mils and put those on the card as well, so all you have to do is find the distance you’re shooting at on the card, then hold over or under based on what the card says.
2. Windage Holds
Mil-dot reticles are great for windage holds since holding is more common for windage than adjusting the turret. The wind is rarely consistent and usually needs to be accommodated for on-the-fly anyway.
If you are going to hold for wind using the reticle, it’s done in essentially the same way, just horizontally instead of vertically. Instead of distance to target, you’re worried about wind speed. The most important thing is going to be knowing in advance how your load reacts to wind at various speeds across various distances, which a mil-dot reticle will not tell you.
For example, .223 Wylde in a 90-degree 20mph crosswind will deviate about 2 inches (depending on the projectile) over the first 100 yards.
The good or bad news is that you’ll have to make all those calculations regardless of how you intend to deal with wind. You can’t adjust with the turret or the reticle if you don’t know how much you need to adjust.
3. Turret Adjustments
Holding with a reticle is just a way of doing on-the-fly, what can also be done using the windage and elevation turrets on the riflescope. Most shooters either hold for both, or they dial for elevation and hold for wind. The inconsistency of wind tends to make dialing for it unrealistic. If you dial for elevation, though, you have to remember to dial back to zero after your shot.
If you have a scope that doesn’t have resettable turrets, you must remember exactly how many clicks you adjusted by or the number your turret was set on before your adjustment. When you zero your scope, if your turrets aren’t resettable (you can pop off the cap and replace them so the 0 marking is on the line), you need to remember the number you landed on.
These can vary slightly, so test out your scope to be sure, but the standard values on a mil-dot reticle are a 1 mil center-to-center gap between dots and a dot width of .2 mil. A dot width of .1 mil is also very common, and usually, the gap between dots will only vary from 1 mil in a low-quality scope.
Neither is better or worse. Technically, MOA is a smaller unit of measurement, which can allow for greater precision and accuracy at longer distances, but if/when you’re good enough at shooting for that to be the difference-maker, you’ll be able to switch between easily enough.
This depends on how far away the target is, and whether the mil-dot is “standard” or not. Assuming the mil-dot is .2 mil in diameter, then at 100 yards the mil-dot would be .72 inches. At 1000 yards it would be 7.2 inches.
Mil-dot reticles are something every shooter should at least try out, in my opinion. The combination of simplicity and versatility is hard to argue with. My personal preference is to get a reticle with a BDC ladder with holds for the specific caliber I’ll be shooting, but that’s because I’m lazy and I rarely shoot at anything more than a few hundred yards away.
Learning to use a mil-dot reticle properly will make you a better shooter in the long run, and they are the favorite of some of the best shooters out there. I advise you to try one and see if it suits your fancy. The worst-case scenario is you don’t love it as much as other reticles, and you’re a little wiser for your trouble.