The AR-15 is less a model of rifle than it is an open-source, modular weapons platform that can be customized for a whole range of applications, from varmint control to taking out 500-pound feral hogs to urban combat. Everything about an individual AR-15 can be changed with aftermarket parts — the caliber of ammunition, recoil, range, weight, length, hold and grip, and on and on.
In the pre-AR-15 era, if you wanted a gun for shooting little groundhogs, a gun for shooting giant feral hogs, and a gun for home defense, you’d buy three different guns in three different calibers and configurations. With the AR platform, a person with absolutely no gunsmithing expertise can buy one gun and a bunch of accessories, and optimize that gun for the application at hand. You can even make an AR-15 into a pistol.
The AR-15 is less a model of rifle than it is an open-source, modular weapons platform
Similarly, the individual members of police and military units can tailor the AR to a specific mission without the help of a professional armorer. Barrels can be swapped out, calibers changed, optics added or removed, and the gun can be totally transformed for every type of encounter, from a long-distance sniper shot at a hostage taker to a close-quarters drug raid in a crowded apartment complex.
So cops and civilians buy AR-15s because that one gun can be adapted to an infinite variety of sporting, hunting, and use-of-force scenarios by an amateur with a few simple tools. An AR-15 owner doesn’t have to buy and maintain a separate gun for each application, nor does she need a professional gunsmith to make modifications and customizations. In this respect, the AR-15 is basically a giant Lego kit for grownups.
Indeed, anyone who tells you that the AR-15 is bad for hunting and home defense has absolutely no idea what they’re talking about, because by definition an AR is a gun that can be exquisitely adapted for those niches and many others.
To return to the Sig MCX that was used in Orlando, the “AR-15ness” of this gun is debatable — it takes many of the same accessories as an AR, and it fits on an AR lower, but unlike a normal AR it has a folding stock and a piston-driven operating system. Because of this, the MCX is the perfect example of the degree to which the “AR-15” is more of a loose collection of standards than a specific collection of parts. Its very existence is emblematic of the adaptability that’s a big part of the AR family’s appeal.
Why the AR-15 is the weapon of choice for everyone (including mass shooters)
If you’re still with me, then maybe you’re beginning to understand why the AR-15 platform is the most popular type of rifle in America. The AR-15’s incredible flexibility, accuracy, and ease-of-use combine with its status as the most thoroughly tested and debugged firearm in military history to make it massively popular with shooters of all stripes, from hunters to home defense buyers to competitors to police. Parts for the AR are available everywhere, and the internet is chock full of maintenance information and training videos.
The rifle’s popularity is almost certainly the main reason why mass shooters increasingly reach for it when they go on a rampage. Think about it: If you’re planning to shoot up a room full of people, are you going to reach for a rare, exotic weapon that you have little experience with, or will you select the familiar option that’s easy to train with and that you have plenty of practice time behind? The answer, for anybody who shoots, is the latter.