After the assault weapon’s ban ended in 2004 the market for the AR 15 absolutely exploded, and the rifle has continued to become more and more popular as it’s used for home defense, hunting, and competition every year. What we saw around the same time was an optical revolution. It was a natural evolution for people to begin scoping their AR platform rifles, even more so after the flat top AR receiver became the norm.
So how much magnification does an AR 15 need?
Before we answer the question we have to set certain criteria. Since the AR platform is so versatile it has dozens of different configurations. The most popular AR 15 platform is the carbine model, based off of the M4 carbine. Other platforms include Marksman’s variants and specialized ARs designed to maximize the platforms accuracy.
Between the combat focused carbine and the hair splitting accuracy of the marksman’s rifle you have another dozen variants in between. So before we answer that question we have to consider what kind of AR 15 you are using.
The carbine variant of the platform is designed to be light and handy. The collapsible stock improves the rifle ergonomics and makes it easier to fire rapidly at closer ranges. This variant of the AR 15 can still reach out and touch a target, but still needs to be capable of close range engagements. With that idea in play, you need to make careful considerations when it comes to optic selection.
I believe a 4 power optic would be perfect for the carbine model. The carbine is still capable of reaching out and striking a man-sized target at 500 yards. A 4 power optic is very efficient at this range. A variable 1 to 4 power optic would also be an excellent choice, with the setting at 1x it’s perfect for close range shooting. These low to medium power levels keep the rifle versatile and allow the shooter to take advantage of the platform’s inherent accuracy.
Options like the Bushnell AR optics and Nikon P223 are examples of simple, affordable optics that match the AR carbine well. If you are looking for a weapon designed for combat applications the Trijicon ACOG is by far one of the best options for the AR 15 carbine, the ACOG with a fixed 4 power can be used as both a red dot and a longer range optic. Other options include the idea of using a magnifier in coordination with an Aimpoint or Eotech.
AR 15 Marksman’s Rifle
A good AR 15 configured to maximize accuracy is an impressive beast. This platform is popular with infantry squads in the Marine Corps and is known as the Mk 12 DM rifle. The same thing can be easily built or bought by an AR enthusiast. You’ll need a scope that can take full advantage of your bull barrel, your free floating handguard, and Geissele trigger.
There are a number of excellent options out there, and the traditional 3 to 9 power is a classic option that still works well, and does meet the needs of the versatile AR 15. Most AR marksman rifles are designed to maximize accuracy while maintaining the AR 15’s rapid fire capability. So the lower magnification levels of the 3 to 9 power magnification range makes it possible to transition with ease from target to target. The higher power makes it possible to strike small targets, like prairie dogs, with relative ease.
You can always go slightly higher or slightly lower in magnification. However, it’s doubtful you’d ever need something with a 42 power magnification. The 14 power Primary Arms FFP would be a decent option, and is an affordable FFP scope. Another excellent option is the Leupold Mark MR/T scope, especially in it’s 2.5 to 8.5 magnification configuration.
The general guideline you want to follow is to use the scope that matches your rifle and your ammunition selection. Surely you could put a 3 to 9 on a carbine and getting good results, but it doesn’t allow the carbine to perform to its max potential. Also, examine the ammunition you are using, and understand that not all ammo is the same. You need to match the long range performance of your rifle and ammunition to get the best results out of your scope.
There is no one size fits all answer to this question, instead, there is a many size fits many different options.