Following on from Understanding Mils, I’m going to try and put that information into the context of Mil-Dot Scope Reticles.

Since a Mil is a unit of angular measurement, and in this case not short for ‘Military’ as people often assume, it would be safe to assume that a ‘Mil-Dot’ Reticle has something to do with angular measurement too.

As a re-iteration, 1 Mil is 1000th measure of the distance. For more info read Understanding Milliradians (Mil, Mil-Rad).

The Mil-Dot Reticle

Mil-dot Reticule Explained

Mil-dot Reticle Explained

So a Mil-Dot reticle is precisely laid out to give known angles at a glance. When you know the representative angles as shown above and what those markings mean at your target distance, it becomes easier to use these for corrections.

For example, if you put a shot on target and it ends up 1 Mil high and 2 Mils Left, you could see the shot placement on your sight and know that you need to adjust 1 Mil down and 2 Mils right with your click correction, OR if time is of the essence you could aim off using the dots and shoot 2 dots right and 1 dot below. Like this:

Mil-dot Shot Placement

Mil-dot Shot Placement

Mil-dot Correction on the fly (Hold Over, Aiming Off)

Mil-dot Correction on the fly (Hold Over, Aiming Off)

So for speed and efficiency, Mil-Dot helps us correct shots that have gone off accurately since we have an accurate scale which we can judge shots.

But that’s not all Mil-Dot can help with.

Mil-Dot Reticle Range Estimation In Yards

Since we know the size in Mils of the various gaps or dots of our sight, and we worked out that the Distance (R) is relative to the target size (1000 x) we can use this information to estimate the distance to target.

Say we have a target that’s a known height. A car wheel for instance, that we know is 15″ in diameter. We can hold the sights over the car wheel and use the size of the object in the sights to gauge the angle it is.

Mil-Dot Range Estimation

Mil-Dot Range Estimation

This gives us 2 pieces of information, from which we can extrapolate the third. 15″ wheel (Tz – Target Size) is 5 Mils (M – Mils) at our Distance (R). So how do we get the distance?

Since we’re working in Millirads, and we want to find the Radius, we need to start by multiplying our Target size by 1000 which will give us the total of 5 radians at this distance. But we only want to know the distance of 1 so we divide that total by the number of Mils we read.

(Tz * 1000) / 5 = Distance to Target

We would be 3000″ from our target in this scenario. That doesn’t help us much so we need to convert that total into Yards (Or Metres, depending on the unit of measure you are working in.

There are 36″ in a yard, so we would divide 3000 / 36.

83.3333 Recurring Yards.

The Target in this scenario is pretty close.

What about Mil-Dot Reticle Estimation in Metres

It works in exactly the same way as I outlined above, perhaps to make things easier if we estimate the size of our target in a metric system rather than that of ye olde time imperial, it might make things a little clearer.

I’ll make a new picture and work this one out in Metric.

Mil-Dot Reticule Estimation 1.5mils

Mil-Dot Reticle Estimation 1.5mils

This time the wheel is either really small, or really far away, and since we know the size of the wheel is 15″  38 cm (+/- .1cm) we can estimate the range using exactly the same formula as above.

(Tz * 1000) / M = Distance to Target

(38*1000) / 1.5 = 25333.3cm

Convert that to metres – and herein lies the beauty of the metric system, divide by 100 (Or simply move the decimal point over to the left by 2)

253.3 Metres to target.

It’s pretty darn simple when you use Mils with Metres.

Why did I Estimate Mil-Dot Range with Yards

Well, whilst it is simple to use Mil-Dot with Mils, and it makes sense, you don’t only find Mil-Dot reticles on Mil-Click scopes. Infact I have 2 MOA-Click scopes with Mil-Dot reticles. Though I only use them for static shooting at known distances the range estimation features are useless, to me, for now. However being able to use the Mil-Dot as a reference point for Hold-Over correction is worth having it in itself, and well, it looks cool, It’s the kind of scope you see on video games and movies, and it’s pretty cool. But now you know how it works, it’s also practical as well as being cool!

When would using Mil-Dot Range Estimation Be Useful?

For Civilians, it would be useful for field target competitions, where you need to estimate the distance to the target in order to score a first round hit. if you know the target is 12 ” you can use the mil-dot to work out the distance and dial in the zero for that distance for a perfect first round hit. Likewise for hunting, where range estimation is everything when taking a shot on live quarry. You don’t always get a chance for a second.

For Military it is invaluable to be able to judge how far away the enemy is quickly. Often soldiers will carry charts of known sized targets at different ranges with their Mil Dot size to range distance. A lot of the time they won’t need it because they train and work with the system so much it becomes second nature, which is the same for hunters, who will often use the dots to aim off to get that quick shot without being seen or heard.

Imperial Mil-Dot Table

Object Size	12"	24"	1Yds	48"	60"	2Yds	84"	96"	3Yds	
0.5 Mils	667Yds	1333Yds	2000Yds	2667Yds	3333Yds	4000Yds	4667Yds	5333Yds	6000Yds	
1 Mils		333Yds	667Yds	1000Yds	1333Yds	1667Yds	2000Yds	2333Yds	2667Yds	3000Yds	
1.5 Mils	222Yds	444Yds	667Yds	889Yds	1111Yds	1333Yds	1556Yds	1778Yds	2000Yds	
2 Mils		167Yds	333Yds	500Yds	667Yds	833Yds	1000Yds	1167Yds	1333Yds	1500Yds	
2.5 Mils	133Yds	267Yds	400Yds	533Yds	667Yds	800Yds	933Yds	1067Yds	1200Yds	
3 Mils		111Yds	222Yds	333Yds	444Yds	556Yds	667Yds	778Yds	889Yds	1000Yds	
3.5 Mils	95Yds	190Yds	286Yds	381Yds	476Yds	571Yds	667Yds	762Yds	857Yds	
4 Mils		83Yds	167Yds	250Yds	333Yds	417Yds	500Yds	583Yds	667Yds	750Yds	
4.5 Mils	74Yds	148Yds	222Yds	296Yds	370Yds	444Yds	519Yds	593Yds	667Yds	
5 Mils		67Yds	133Yds	200Yds	267Yds	333Yds	400Yds	467Yds	533Yds	600Yds	
5.5 Mils	61Yds	121Yds	182Yds	242Yds	303Yds	364Yds	424Yds	485Yds	545Yds	
6 Mils		56Yds	111Yds	167Yds	222Yds	278Yds	333Yds	389Yds	444Yds	500Yds	
6.5 Mils	51Yds	103Yds	154Yds	205Yds	256Yds	308Yds	359Yds	410Yds	462Yds	
7 Mils		48Yds	95Yds	143Yds	190Yds	238Yds	286Yds	333Yds	381Yds	429Yds	
7.5 Mils	44Yds	89Yds	133Yds	178Yds	222Yds	267Yds	311Yds	356Yds	400Yds	
8 Mils		42Yds	83Yds	125Yds	167Yds	208Yds	250Yds	292Yds	333Yds	375Yds	
8.5 Mils	39Yds	78Yds	118Yds	157Yds	196Yds	235Yds	275Yds	314Yds	353Yds	
9 Mils		37Yds	74Yds	111Yds	148Yds	185Yds	222Yds	259Yds	296Yds	333Yds	
9.5 Mils	35Yds	70Yds	105Yds	140Yds	175Yds	211Yds	246Yds	281Yds	316Yds	
10 Mils		33Yds	67Yds	100Yds	133Yds	167Yds	200Yds	233Yds	267Yds	300Yds

Metric Mil-Dot Table

Object Size	25cm	50cm	75cm	1m	1.25m	1.5m	1.75m	2m	2.25m	2.5m	2.75m	3m	
0.5 Mils	500m	1000m	1500m	2000m	2500m	3000m	3500m	4000m	4500m	5000m	5500m	6000m	
1 Mils		250m	500m	750m	1000m	1250m	1500m	1750m	2000m	2250m	2500m	2750m	3000m	
1.5 Mils	167m	333m	500m	667m	833m	1000m	1167m	1333m	1500m	1667m	1833m	2000m	
2 Mils		125m	250m	375m	500m	625m	750m	875m	1000m	1125m	1250m	1375m	1500m	
2.5 Mils	100m	200m	300m	400m	500m	600m	700m	800m	900m	1000m	1100m	1200m	
3 Mils		83m	167m	250m	333m	417m	500m	583m	667m	750m	833m	917m	1000m	
3.5 Mils	71m	143m	214m	286m	357m	429m	500m	571m	643m	714m	786m	857m	
4 Mils		62m	125m	188m	250m	312m	375m	438m	500m	562m	625m	688m	750m	
4.5 Mils	56m	111m	167m	222m	278m	333m	389m	444m	500m	556m	611m	667m	
5 Mils		50m	100m	150m	200m	250m	300m	350m	400m	450m	500m	550m	600m	
5.5 Mils	45m	91m	136m	182m	227m	273m	318m	364m	409m	455m	500m	545m	
6 Mils		42m	83m	125m	167m	208m	250m	292m	333m	375m	417m	458m	500m	
6.5 Mils	38m	77m	115m	154m	192m	231m	269m	308m	346m	385m	423m	462m	
7 Mils		36m	71m	107m	143m	179m	214m	250m	286m	321m	357m	393m	429m	
7.5 Mils	33m	67m	100m	133m	167m	200m	233m	267m	300m	333m	367m	400m	
8 Mils		31m	62m	94m	125m	156m	188m	219m	250m	281m	312m	344m	375m	
8.5 Mils	29m	59m	88m	118m	147m	176m	206m	235m	265m	294m	324m	353m	
9 Mils		28m	56m	83m	111m	139m	167m	194m	222m	250m	278m	306m	333m	
9.5 Mils	26m	53m	79m	105m	132m	158m	184m	211m	237m	263m	289m	316m	
10 Mils		25m	50m	75m	100m	125m	150m	175m	200m	225m	250m	275m	300m

What about on my scope that zooms?

With a scope that zooms, its important to know whether the reticle increases in size with the zoom so that 1 Mil Readout at 5x zoom is the same as 1 Mil Readout at 25x zoom, or whether the reticle stays the same size when you zoom.

This is referred to as First Focal Plane and Second Focal Plane.

The Majority of scopes on the market are Second Focal Plane, where the reticle stays the same size regardless of the Zoom. This causes issues with everything we’ve learned above. Since the markings stay the same, but our objects get bigger, we cannot use the Mil-Dot to estimate the range, as it would be impossible to judge the exact amount of Zoom and calculate the increase in the reported size in Mils. With these scopes you would have to make sure that all adjustments are made either with hold over as shown above (providing the zoom doesn’t move between shots) OR by calculating precisely how many clicks without referring to the Mil-Dots as reference for how much to click.

Sounds exhausting.

So First Focal Plane are where to be if you want to use the markings in your scope, or Mil-Dot Reticle to be able to adjust based on Mil-Dot markings, or Range estimation as shown above. These scopes are out there, but they’re fairly expensive.

For More information on FFP and SFP reticles head to Primal Rights, Inc where they explain it in far greater detail than I have.