What is a red dot sight?
A red dot sight uses a reflective glass lens to gather light from an LED which projects an illuminated reticle—typically a dot or a circle with center dot—superimposed on the field of view. The greatest benefit of using a red dot sight is increased speed of acquiring a target without loss of accuracy.
A red dot sight makes a highly visible aiming point for the user. Unlike traditional magnified scopes, you can aim with a red dot sight with both eyes open and it has unlimited eye relief. Iron sights require users to align both the front and back sights to aim at a target, while red dot sights are designed to get the shooter on target very quickly.
To answer the question, “are red dot sights accurate?” and get the most out of your red dot sight, you must use the sight correctly.
Bindon Aiming Concept
As noted above, red dot sights are designed specifically to be used with both eyes open. This is called the Bindon Aiming Concept. When we keep both eyes open, we get the benefit of focusing both on the target and the reticle. Your dominant eye sees the reticle and the target, while your non-dominant eye sees only the target, resulting in what is called a stereopsis image. The image from the dominant eye is overlaid with the image from the non-dominant eye. This process happens subconsciously and nearly instantaneously. This not only naturally leads to faster target acquisition and the probability of an accurate shot; stereopsis also allows a failsafe method of target acquisition in case your red dot’s line of sight is blocked.
Red dot sights have 1x or a true zero magnification. Instead of concentrating on getting the reticle centered on your target, the illuminated reticle of a red dot sight happens as fast you can raise your firearm and see the dot. Remaining focused on the target, as soon as the dot is at your aiming point, you can fire an accurate shot.
Using the Bindon Aiming Concept also allows shooters to remain situationally aware with a wide field of view. This is particularly useful in self-defense, law enforcement and military situations, as you can still see your surroundings and identify further threats.
Parallax
To a certain degree, red dot sights are nearly parallax-free. Parallax is what you experience when using magnified riflescopes. When you move your head, the reticle seems to move around the target. This is caused by the reticle not focusing at the same distance as the target. With a red dot sight, your head position will not affect the red dot sight’s accuracy.
No optical sight, though, is 100% parallax-free as parallax will occur at some point at closer ranges. This can be clearly seen when a red dot is mounted in an absolute co-witness setup. In this setup, the reticle will “swim” all around the front iron sight. The typical red dot sight will be parallax-free from 25 to 50 yards to infinity.
MOA Dot Sizes
Another important factor affecting the accuracy of the red dot sight is the size of the dot.
The illuminated reticle, whether it be a single red or green dot or a circle with subtensions and center dot, is measured in minutes of angle (MOA.) The minute of angle is a unit for angular measurement of a circle. 1 MOA is equal to 1.047 inches at 100 yards, rounded down to 1 inch. For example, a 1 MOA dot will appear to be 1 inch big on at target 100 yards out. A small MOA dot will be harder to see, especially at longer distances. A large MOA dot, especially at the highest brightness level, will be very easy to see but may cover too much of your target to precisely hit where you’ve aimed.
3 to 5 MOA dots—with 3 being the most popular—lay in between the middle of small and bigger dot sizes. Since most red dot sights have adjustable brightness, the 3 to 5 MOA dot is the most accurate in most shooting situations from home defense in tight quarters to medium range steel target shooting or hog hunting.
Picking out the right reticle size will help or hinder your accuracy with a red dot.
For more about how to chose which dot size, click here.
Though magnified riflescopes and iron sights with extensive training and practice are extremely accurate, the red dot sight’s design is inherently more so with the addition of speed. The illuminated dot stays parallel with the sight’s optical axis, so the point of aim is always in line with the point of impact, as well as the red dot always remaining in focus no matter how far away the target.
The only area in which the red dot’s accuracy does not excel is longer distances. CQB and medium-range target shooting, competition, self-defense, and predator and varmint hunting, some even use a red dot sight while turkey hunting, are all where the red dot sight is most useful.
For more on red dot sights, read the following helpful articles:
http://sightmark.com/blog/index.php/2018/01/12/how-to-shoot-with-a-red-dot-sight/
http://sightmark.com/blog/index.php/2018/03/16/m-spec-red-dot-sight-is-ready-for-duty/