The distance from the target is what should be determined first. The accuracy of this value is used to determine many other variables. There are several methods for determining the distance to the target.
Lasing
Laser range finders are now common equipment with most hunters and snipers. These relatively inexpensive devices are small, add little weight to the shooters kit, and function well. There are two cautions concerning lasers discussed below.
First of all, the usage of any laser on the modern battlefield is becoming risky. Almost every soldier and major weapon’s platform (such as M1 tanks and Bradley fighting vehicles) have been using one form or another of lasers for over a decade. Laser detection is becoming more of a topic of concern among professionals. With all of those beams of light bouncing all over the place, it won’t be long before our enemies implement counter-measures that can track, plot and detect any sort of laser.
Perhaps even more importantly, battery-operated devices can be a pain in the field.
Management of spares, failure at just the wrong time, moisture, shock and general wear and tear can make depending on anything electronic risky. Learn to manage your electronic helpers well and always have spare batteries.
If you can’t afford or don’t believe in laser range finders, there are numerous manual methods used to determine the range to a target. One of the most widely accepted is the reticle of the optic.
Reticles
The reticle of early riflescopes was a simple intersection of a vertical and horizontal line within the viewing area of the scope. The shooter placed the intersection on the target and squeezed the trigger. This system didn’t account for bullet drop, wind or any other factors – those were up to the shooter to determine and adjust for.
Today, practically every optic manufacturer has numerous different reticles from which to choose. Some of these are even caliber specific for those of us who slept thru math class. A few scope makers will actually build you a custom optic with the ballistics information you provide, which makes more sense to me than an off-the-shelf model built with a generic .308 reticle. My logic for avoiding these types of reticles is the other factors listed above, such as humidity, combined with the fact that there are dozens of different bullets with unique ballistics for each caliber would make any .308 reticle incorrect for a large percentage of weapons.
There many reticle options available, each having a slightly different method of estimating bullet drop and distance. It would take an entire book dedicated to this narrow topic to cover them all. Given the rate at which new scopes hit the marketplace, the book would be out-of-date before leaving the presses.
By far the most common reticle is called the Mil-Dot. Since this is the optic used by the majority of military snipers, many people believe the “Mil” in the name refers to military, but it doesn’t. Mil-Dot reticles are scaled at mill radians – thus the Mil. As best as I can determine, this method of estimating distance to target is an off-shoot of the WERN formula which is used to range mortars and other long-range weapons. According to several sources, this reticle was designed for the Marine Corps in the late 1970s.
These days, there are even several different revisions or types of Mil-Dot reticles. I recommend you research how a specific reticle is set up and understand its intended usage before
purchasing any optic. The following is an example of how to use a reticle to determine range: To begin with, you have to know the areas each type of hash mark or dot is designed to cover. The drawing below (Figure 12.11, not to scale) depicts a typical Mil-Dot reticle:
Editor’s Note: In the process of conversion for printing, some formats may depict the dots slightly off
center of the horizontal and vertical lines. On an actual reticle, the dots are centered on the lines.
Next, you must determine at what magnification the optic is designed to be “ranged” with. On most Mil-Dot optics, a setting of 10x is used, but you should verify this critical point. Set the scope to that magnification. The area covered by each feature of the reticle, at 100 yards, is noted below:
Number Description Size of area at 100 yards
1 A single mil-dot .75 inches @ 100 yards
2 Center to center - two dots 3.6 inches @ 100 yards
3 Four dots – center to center 18 inches @ 100 yards
4 Varies from scope to scope
The area covered at 1,000 yards would equal each value divided by 10:
Number Description Size of area at 1,000 yards
1 A single mil-dot .075 inches @ 1000 yards
2 Center to center - two dots .36 inches @ 1000 yards
3 Four dots – center to center 1.8 inches @ 1000 yards
4 Varies from scope to scope
The area covered at 500 yards would equal the value at 100 divided by 5.
The area covered at 400 yards would equal the value at 100 divided by 4, and so on. The key to using a mil-dot is knowing the height or width of a fixed object and measuring it with the reticle to determine the object’s distance. For example, the average vehicle wheel
(passenger car) is 18 inches in diameter. Perhaps the average fence post in your part of the world is 42 inches high. The average man is close to 6 feet tall.
Once you determine an object to focus on, estimating the distance is easy.
Let’s say you are trying to determine the distance to a target in proximity to a pickup truck. Use the following steps:
Set your optic to the proper magnification for ranging.
You know the wheel is most likely 18 inches. You know the wheel measures 2 mils. Here is the math:
((18 divided by 36) x 1000) divided by 2 You divide the size of the target by 36 to convert inches to yards. That solution is divided by 1,000, a fixed value.
That solution is divided by 2, the number of mils. 18 / 36 = .5 .5 x 1,000 = 500
500 / 2 = 250 The target is estimated at 250 yards away.
I always try and use an object’s width rather than height. This is because angles (being above or below the target) will distort height, but not width. If you are on flat terrain and relatively level with the target then either dimension will work fine.
Many shooters develop a cheat sheet showing a matrix of distances as compared to sizes in inches. This is different than the Data on Previous Engagements (DOPE) for a specific rifle. If you prefer this method to doing math in the field, then by all means run a spreadsheet, print it off, and laminate it.
Another method is to use a ballistic computer. There are two basic classes of such devices, one being manually operated, similar to a slide rule, and the other being electronically based – similar to a calculator. There are even ballistic software programs that can be loaded onto smart phones for free.
Many professional shooters go with a simple handheld calculator and a cheat sheet(s) of formulas. A solar-powered calculator with battery backup is not an expensive item, and there are models that are robust, built for outdoor use. These can most often be found in home improvement stores labeled as a contractor’s calculator.
Your final kit is up to you, your budget, and your area of operations. In jungle and seaside environments, electronic devices are more suspect. Night operations require even more consideration.
Focus Estimation
Many riflescopes now have the capability to adjust the focus onto a target and thus provide range estimation. I have found these “distance knobs” to be hit or miss, and I would never take a critical shot based on this information. Your equipment may be different and provide accurate distance information. So far, even with higher cost optics, these have not proven to be reliable for me.
Recommendation
Today, there are riflescopes that estimate range for you. Most of these models have a built-in laser to determine distance. There are computers that you can attach to your scope, and they will adjust the knobs automatically for the shot. While I’m not quite ready to take the plunge on a full-out technology based solution, the accuracy achieved by using lasers is difficult to argue with. The military issues laser range finders to their long-range shooters as well as teaching them manual methods as a backup.
If your budget allows, I would invest in a laser range finder and use it to verify my manual estimations (using mil-dot or other method) while training. If the electronic device fails for any reason, you still know how to do it the old-fashioned way.
Should you decided to invest in a laser device, I have two tips you should consider: 1. Go ahead and get a device that compensates for angle as well (discussed above).
2. Make sure you pick a unit that is capable of the range you are shooting. Many models are limited to 500 yards or are intended for bow hunters. A model that is designed for 1,000 or 1,200 yards isn’t that much more money.
Using a combination of manual estimation and electronic helper is a combination that can’t be beat and should allow you to put lead on target more often than not.