AR Optics: Scope vs Red dot: 5 Big Differences

Or, you could always use both!

When getting a new AR, the biggest accessory purchase to consider is what sight to use on it. While some people continue to use antiquated iron sights, more and more people are using optics. The two main types of optics are red dots and magnified scopes. These are just a few of the things to keep in mind when purchasing an optic.





This decision comes down to what you want to use it for. If you plan on doing up close and personal run and gunning, the low to zero magnifications of most red dots is will better allow you to transition between targets seamlessly. If you’re looking for longer range shooting, the magnification of a scope, which can be any where from 0-20 times in commonly available scopes, though 3-9 times variable zoom is extremely popular. is a real advantage, as it allows you to be able to pick out your target from much further away, as well as to shoot much more accurately.



Duracell AA Battery


Nearly all red dots, with  few exceptions of some high end reflex sights, like the Trijicon®  Reflex, use batteries as the only source of light, so if they die, the sight is no longer usable. While some may see this as an issue, given the fact that most modern red dot sights have battery lives measured in days, even months, not hours.

Red dot sights use a wide variety of batteries, from AA batteries to CR2032 watch style batteries. Some sights, such as the Aimpoint Micro T1, have lives measuring at 5 YEARS. Scopes, on the other hand, don’t require batteries to work. While some may have illuminated cross hairs, this will still work perfectly with a dead battery. So while something to consider, batteries, given modern red dot’s battery life, aren’t as big of a deal breaker as some people make them out to be. 




Most scopes suffer from parallax. Parallax is  what happens when your eye isn’t at exactly the same place it was when the gun was sighted in, and this slight difference causes the cross hairs to not line up correctly with the target. The further away your eye is from where it was when the gun was sighted in, and the further away the target is, the more exaggerated the effects of this are.

Red dot sights, on the other had, are made to have no parallax. As long as the red dot’s aiming dot is covering where you want to hit, and you account for other factors that can affect your shot, it will hit where you want it to every time, regardless of if your head is on the exact correct spot.




While scopes are much better when it comes to precision, red dots are king when it comes to speed. Due to how the dot appears to be on the same focal plain as your target, your eyes have a much easier time putting the dot where it needs to be fast; with scopes, you have the issue of a more ambiguous aiming point, as opposed to a giant red dot.

Also, any magnification makes it take a bit longer to get your sight where you need it to be. So red dots are better for getting a shot on target faster, while scopes are better for getting the shot exactly where you need it.




Most dots on red dots are about 2-4 minutes of angle (MOA) in size. This means it will cover about 2-4 inches of your downrange target at 100 yards; at 200 yards, it will cover 4-8 inches of your target, and so on. (note: technically 1 MOA at 100 yards is 1.047 inches, so at 1,000 yards, 1 MOA is 10.47 inches, but even at the range, the difference is negligible, so most people just use 1 inch at 100 yards.)

This means that you can’t be completely sure where your shot will hit, within the dot. With a scope, on the other hand, you have only a negligible amount of your target covered, allowing much more precise shot placement. Also, with magnification, you can aim at a much smaller point, and as the old saying goes, “aim small, miss small”.

In the end, it comes down to your choice. Be sure to consider all of the above factors carefully, and weigh out what you intend to use the rifle for, and ensure that your choice fits your intended purpose. Happy shooting!



And please don’t make your AR look like this!