Is a Home Defense AR-15 A Good Idea?

There are a lot of people who have a home defense AR-15 rifle or something similar to it; in other words, they keep a civilian version of a weapon that’s taken to war in case of home invasion or something along those lines. Is that overkill and dangerously so, or is that a totally valid choice?

Most people are content with a handgun. Most people who carry for self defense are as well, which is why so many people get a holster, gun belt and a concealed carry license so they can concealed carry.

Tactical AR-15 Should Perform Perfectly

Part of the reason why so mean people consider a tactical AR-15 for home defense is that it’s an ideal implement to do so with. The AR-15 is the civilian version of the same rifle (M4 and/or M16) that our military takes into battle (as well as those of a few other countries) so it’s certainly proven to be a viable firearm and cartridge to…we’ll say marginalize a threat.

Given it’s service history both with armed forces and paramilitary police, such as SWAT teams and equivalents in federal law enforcement, it can work in close quarters as well as in the field, so it’s not like it can’t be used effectively in more confined spaces.

Since the AR platform is also semi-automatic, follow-up shots are a cinch compared to a bolt or lever action, and certainly compared to break-action rifle. (Granted, the latter is almost exclusively single shot.) Heck, if the gun jams the butt makes a much better bludgeon than a pistol does (though a good revolver can certainly do wonders with this use) and you can even stick a bayonet on the thing and poke holes in the bastard.

Attestation to .223 Penetration

However, where it begins to be less of a viable home defense round is the issue of 5.56mm/.223 penetration. Compared to a pistol round, it is a very powerful cartridge. Among rifle cartridges, the .223 Remington/5.56x45mm NATO cartridge is the Babytown Frolics. By comparison, the .270 Winchester (which some consider small and puny) slugs like George Foreman.

However, rifles are meant to hit targets from great distances. When a bullet exits the barrel of an AR, the projectile is moving at three times the speed of most pistol ammunition. The .223/5.56 usually has a velocity around 3,000 feet per second; only a few magnum pistol rounds exceed half of that.

Greater speed equates to greater penetration. This is why JHP rounds are recommended for handguns. AR-15 ammunition is capable of penetrating steel plate from more than 100 yards away, so point-blank range in the home may send a bullet through the intruder, the wall behind him, through a house’s exterior and into the street.

But will it though? Viscous drag on a very fast projectile slows it down considerably and can even fragment it. A hard surface, such as thin steel plating (say of a car door) won’t slow a high-speed round down, but a softer material will.

Furthermore, .223 fragmentation rounds have been engineered for defensive purposes and penetrate far less than one might think. For instance, check out the drywall test from HowIDitIt.org.

In the HowIDidIt test, multiple calibers (several .223 rounds, including fragmentation rounds, 7.65mm, 9mm, .380, .45 ACP and 12-gauge 00 buckshot) were sent through three pieces of drywall. The first was five feet away from the shooter, the second ten feet behind and the third ten feet behind the second.

The .223 fragmenting ammunition barely got through the second wall in most cases. Of the pistol rounds, the 9mm may have gone through the third wall if not for bad aim, and the .45 ACP rounds (230-grain FMJ) went through all three easily. The .380 went through the first wall and stopped short of the second. The buckshot went completely through all three.

Home Defense AR-15 Could Well Be Viable

One test by one website doesn’t mean that a home defense AR-15 is totally viable. Another site, TheBoxOTruth, did a similar test and found .223 rounds went through four walls of drywall, though they used different ammuntion, including full metal jacket (or “hardball”) rounds that easily penetrated four sheets of drywall at similar spacings. However, HowIDidIt used different ammuntion, so it isn’t an apples-to-apples comparison.

They also tested reduced recoil 00 buckshot (penetrated all four walls) and birdshot (penetrated the first, and stopped in the surface of the second wall) as well.

Two tests on the internet aren’t conclusive at all. This doesn’t mean an AR is the perfect home defense gun, but it would appear to suggest that if you are going to, you probably shouldn’t use full metal jacket rounds. As long as you aren’t loading hardball…it’s a perfectly viable implement of home defense.