Everyone knows, at least according to the news, that an AR-15 rifle is capable of leveling an entire city block and creating a rupture in the San Andreas fault. So, why on earth would anyone want to choose an AR-15 or similar rifle for home defense? Well, when you examine the issue with consideration of the pros and cons in several different categories, it turns out that the AR-platform rifle, aka the modern sporting rifle (MSR), can make an ideal home-defense option. Let’s take a look at how the AR stacks up against shotguns and handguns in a few relevant categories.

Ease of Use Under Stress

There are three primary factors that determine how quickly and accurately you can hit a target with a firearm: sighting (sight radius), trigger control, and recoil.

Sight radius is the distance between front and rear sights. The farther apart they are, the easier it is to keep the sights lined up with the desired impact point. If sights are close together, it's much more difficult to achieve and maintain perfect alignment. If you had a pistol with front and rear sights a couple of inches apart, the slightest sight alignment problem could result in a miss of several feet down range. With a long gun, you have to work pretty hard to get a miss that big at self-defense distances because the long sight radius makes alignment much more forgiving.

Most handguns require a force between 5 and 12 pounds to operate the trigger. Handguns also usually weigh less than three pounds, so it takes some skill to exert enough force to operate the trigger without allowing the gun to move off target. Rifles weigh six pounds (or more) and have triggers in the three to five-pound range give or take. It’s much easier to fire a rifle without moving the sights off target.

While recoil takes place after the bullet has left the barrel, the anticipation of it can cause all manner of bad habits like flinching as one fires the shot. Most shooters can be more accurate with a low-recoil firearm because they’re not physically anticipating post-shot abuse.

Using an AR Rifle

At closer home-defense ranges, modern sporting rifles are far more forgiving and easier to shoot accurately than handguns due to long sight radius and light trigger pull relative to the weight of the gun. They also have light recoil and usually don’t cause shooter flinching.

While an AR rifle requires both hands, there is virtually no recoil.
While an AR rifle requires both hands, there is virtually no recoil.Tom McHale

Using a Handgun

No one will argue with their convenience and portability (we’ll get to that in a minute), but handguns aren’t inherently easy to shoot well under stress. There’s a reason that somewhere over 80% of shots fired by police at close range miss their targets. With a short sight radius and need for perfect trigger technique, it’s surprisingly easy to miss your target from just feet away during a chaotic fight.

Even when shooting with one hand, most pistols have very manageable recoil.
Even when shooting with one hand, most pistols have very manageable recoil. When using both hands, recoil and muzzle flip are minimal and it’s easy to fire multiple shots if necessary.Tom McHale

Using a Shotgun

Like ARs, shotguns have a long sight radius and are easy to aim. And yes, you do have to aim them at home-defense distances. However, 12-gauge models have recoil that can be classified as “stout” and many shooters don’t do well with them for that reason. Recoil is one reason that many choose a 20-gauge shotgun for home defense. Effectiveness is still solid, but with significantly reduced recoil. Smaller shotguns like the .410 offer even more control, but are questionable as far as reliable stopping power.

Even when using a strong stance and both hands, 12-gauge shotgun recoil is nothing to sneeze at.
Even when using a strong stance and both hands, 12-gauge shotgun recoil is nothing to sneeze at.Tom McHale

Stopping Power

Nothing is guaranteed to stop a determined attacker. There are examples of armed encounters where bad guys kept fighting after being shot 5, 10, 20, and even more times. Sergeant Gramins of the Skokie, IL Police Department encountered an armed bank robber back in August of 2008. When the suspect suddenly opened fire on Gramins, the officer returned fire with his .45-caliber Glock 21, hitting the perpetrator 14 times. Six of those shots were in supposedly fatal locations. Yet the suspect continued to fight, even to the point of retrieving a second handgun from his vehicle to continue shooting.

In terms of pure kinetic energy, there’s a huge difference between the pistol, AR-type rifle, and shotgun.
In terms of pure kinetic energy, there’s a huge difference between the pistol, AR-type rifle, and shotgun.Tom McHale

In another incident, after being fired upon by a violent suspect, Officer Peter Soulis had to shoot his attacker 21 times with premium .40 S&W ammunition before the perpetrator gave up the fight. 17 of those shots hit "center mass."

In yet another incident, Pennsylvania officers hit a criminal with 17 shots a criminal, 11 of which were fired from an M4 carbine, before ending the fight.

While they may have sustained mortal wounds, these perpetrators continued to fight until their body figured that out. Handguns are relatively weak compared to rifles and shotguns, and when you remove all the hype and drama, what they do is make holes.

An attacker may not stop until enough holes are made to create blood pressure loss or until something structural or “electrical” is sufficiently damaged.

Do some people stop after being shot once? Sure. Do others continue to fight after absorbing pistol, rifle, and shotgun rounds? Sure. There are too many variables at play to predict what will stop a determined aggressor. With that said, the odds of a quick stop are statistically different for ARs, handguns, and shotguns.

AR Rifle Damage

ARs shoot light and fast bullets and rely on velocity to incapacitate. While there are never guarantees, a small and light bullet moving close to 3,000 feet per second tends to inflict more fight-stopping damage than a heavier handgun bullet traveling in the 1,000 feet per second range. Studies have shown approximate one-shot stop rates at around 60 percent - near double that of handguns. Mathematically, a standard 55-grain AR bullet delivers approximately 1,200 foot-pounds of energy. Hold that thought for a hot second.

Handgun Damage

Make no mistake, handguns can stop attacks too. However, as “one shot stoppers” they don’t have as good of a record as rifles or shotguns. Depending on caliber, single-shot stop rates are in the 30 to 40 percent range, and on average it takes two point something rounds to incapacitate based on average historical data. Take “average” data for what it’s worth – your potential scenario may or may not be “average.” Regarding energy, handguns deliver 400 foot-pounds of energy, give or take depending on caliber.

Shotgun Damage

Like rifles, shotguns tend to have far better one-shot stop records. From limited historical study, shotguns approach 70 percent success for single-shot stops. A 12-gauge shotgun load may deliver 2,500 foot-pounds of energy, over six times that of an average handgun.

Pistols just don’t have “knockdown” or “stopping” power.
Pistols just don’t have “knockdown” or “stopping” power. They make holes. While certainly lethal, they may or may not quickly stop a determined attacker.Tom McHale

Penetration

When firing a gun in the home, amidst all the other things to worry about like saving your life and protecting your family, you have to worry about where your shots end up. If you fire a round that misses your target, how many walls will it travel through and where will it come to rest?

Are you sure that it won’t leave the confines of your home? Will it pass into another room and present a risk to a family member? If you live in an apartment, what about the neighbors above, below, and beside you?

The actual relative penetration of different types of firearms and ammunition are where things might surprise you.

AR Rifle Penetration

Contrary to what you might assume, those light and fast bullets don’t penetrate most things nearly as well as heavier and slower handgun bullets. A couple of layers of drywall is enough to disrupt the flight path of an AR projectile to the point of tumbling and fragmentation.

Federal Guard Dog ammunition
Federal Guard Dog ammunition is a full metal jacket expanding design. The bullets expand when striking most any object, so they can be beneficial for in-home use as they lose energy quickly.Tom McHale

While nothing is entirely predictable, I’ve shot full metal jacket 55-grain bullets that start to tumble and rapidly lose energy after passing through two or three sheets of drywall, and that’s not counting other potential barriers in homes and walls like wood and insulation. When using “varmint” ammo like Hornady V-Max, those bullets start to fragment after a couple of drywall layers.

Handgun Penetration

In the home environment, handgun bullets generally tend to penetrate more layers of drywall and wood than do light AR projectiles. Without the extreme velocity and having more mass, handgun bullets tend to plow right on through material with far less disruption. They’re also designed to hold together after passing through barriers like clothes, wood, steel, and automobile glass, so walls aren’t a significant barrier.

There are some expanding full metal jacket loads like Federal Guard Dog that will expand when hitting most any barrier. They'll still penetrate multiple layers of drywall but will lose energy and penetration power rapidly after the initial impacts.

The shot in the lower part of the targets is a 9mm pistol bullet
The shot in the lower part of the targets is a 9mm pistol bullet. It traveled straight through four sets of walls unimpeded. The other shot was a full metal jacket 55-grain .223 Remington bullet. It started to tumble and lose energy after passing through the second wall.Tom McHale

Shotgun Penetration

How shotguns perform indoors depends entirely on the type of shotgun shell one chooses. Birdshot loads filled with hundreds of tiny #7 ½ or #8 pellets slow down very quickly, especially after passing through a sheet of drywall. After traveling 10 feet or so, they also tend to spread out and in the process lose much of whatever penetration energy they had at the start.

At the other extreme, slugs or buckshot shells fling comparatively heavy projectiles at velocities of 1,200 to 1,600 feet per second. You can think of a 00 Buckshot shell as firing eight to 15 .30-caliber bullets – all at once. Buckshot and slugs also tend to penetrate drywall and wood just as handgun bullets do.

some bullets fragment
Varmint AR bullets like the Hornady 55-grain V-Max will begin to fragment into many pieces after enchanting a few layers of drywall material.Tom McHale

Maneuverability

If we’re talking home-defense, you have to consider maneuverability in your planning. While no one wants to engage in a game of cat and mouse with a home invader, you may not have a choice. If you don’t have the option to barricade in place and wait for help, you may need to move around your home in the dark. You might need a free hand to call for help or deal with children, open doors, hit light switches, and that might impact your firearm type selection.

While ARs are easy to aim and control, they require two hands and are significantly larger.
While ARs are easy to aim and control, they require two hands and are significantly larger. Maneuvering in tight indoor spaces is more challenging than with a handgun.Tom McHale

Moving with an AR Rifle

Unless you’re a video game character and can duel wield rifles, one in each mitt, you’ll need both hands to carry and fire an AR. It’s also longer than a handgun, so moving around the house and through doorways is far more cumbersome.

However, ARs do have some features that mitigate the size disadvantage. Most AR stocks are collapsible so that you can shorten the overall length of the rifle. You can also choose an AR pistol design. While a little harder to control, those can have short barrels and short braces on the back end, so they're relatively compact. However, these options aren't permitted by law in every state, so that's something to consider as well.

Moving with a Handgun

Handguns win “hands down” in this category. You can carry and fire with one hand, and there is nothing more compact. The relative ease of one-handed operation means you can operate a light or phone, carry a child, or even push or fight with the other. As far as maneuverability, when tucked in close, a handgun is essentially part of your body. When coming through a doorway, you won't be exposing the barrel first as with a rifle or shotgun.

Handguns are compact and maneuverable.
Handguns are compact and maneuverable. They also allow you to use your other hand with a phone or flashlight.Tom McHale

Moving with a Shotgun

Shotguns have to have at least an 18-inch barrel by federal law, so they’re even longer than the average AR. Most have fixed stocks so you won’t get the advantage of being able to shorten the back end for maneuverability. Of course, you can add an adjustable stock and you can go the short-barreled shotgun (SBS) route, but it requires a tax stamp, paperwork, and waiting.

Some newer shotgun options, like the Remington TAC-14 and Mossberg 590 Shockwave, are extremely short and nimble, but they lack a stock, which makes them hard to control and operate. Adding a stock is illegal unless you have the aforementioned tax stamp for an SBS, but you can add a brace like those made for AR pistols, with a special adapter, which does help increase stability.

Capacity

In a home defense situation, you might come face-to-face with one intruder. Or you might not. More and more home invasions involve multiple perpetrators, so a low-capacity handgun like a revolver or compact pistol might leave you lacking in the available shots category, and that’s a bad place to be.

AR Rifle Capacity

Unless you live in an area where there are arbitrary capacity restrictions, a standard .223 caliber AR mag holds 30 rounds. If that’s not enough, the box magazine design makes for a quick 30-round reload. Even larger caliber ARs offer capacity of 25 rounds give or take.

Handgun Capacity

Since we’re talking home defense, we’ll assume that you choose a full-size handgun. Revolvers will limit you to maybe eight rounds at best, but many affordable service pistols will pack 15 to 17 rounds per magazine of 9mm. Some pistols come with bigger mags, like the SIG Sauer P320, which is available with 21-round mags, and Glock magazines can be purchased in a variety of capacities, but they start getting really long and heavy.

The AR wins the capacity category. Most offer 30-rounds and easy reloading.
The AR wins the capacity category. Most offer 30-rounds and easy reloading.Tom McHale

As caliber size goes up, capacity goes down. With a .40 S&W you sacrifice three or four rounds; with a .45 ACP, the difference can be substantial: the Smith & Wesson M&P9 in 9mm has a capacity of 17 rounds, the M&P45 in .45 ACP only holds 10 rounds in its magazine.

As with ARs, pistols are easy to reload with fresh magazines.

Shotgun Capacity

Shotguns dominate in the effectiveness category but at a cost. The simplest designs like an over/under offer two shots before reloading is necessary. Standard pump and semiautomatic shotguns might hold five shells in the magazine tube. With some models and magazine tube extensions, you can bump capacity to eight or nine rounds.

While some configurations can hold even more, your rig will start to get long and bulky quickly—and even with options like the Remington 870DM and the Mossberg 590M that use detachable box magazines, shotgun ammo gets real heavy real fast.

Noise and Concussion

Different firearms produce different noise levels, some of which might be intolerable in a small room.
Different firearms produce different noise levels, some of which might be intolerable in a small room.Tom McHale

Shooting anything in the confines of your home will be loud – very loud. With that said, some guns are louder and more concussive than others. Whether that’s a significant factor in an adrenaline-charged defensive encounter is up for debate, but we’ll consider the differences nonetheless. Remember that decibels are measured on a logarithmic scale, so a small numerical decibel difference is quite significant - a three-decibel increase represents a doubling of sound energy.

AR Rifle Noise

An unsuppressed modern sporting rifle cranks out about 165 decibels per shot, putting it in the “louder” category of firearms. To put that in perspective, that’s like having a top fuel dragster in your bedroom. Adding a suppressor may reduce that level to about 135 decibels. The suppressed sound level is somewhere between the noise level of a chainsaw and aircraft carrier deck.

Handgun Noise

Handguns are quieter, usually about 158 decibels. Suppressing your pistol will knock that noise level down to 130 dB.

Shotgun Noise

Shotguns generate roughly the same amount of noise as a .223 AR-15 at 165 decibels. While possible to suppress, the added bulk to already large guns makes it less practical for in-home use.

Conclusion

The most common misconception is that AR-type rifles are “too powerful” for in-home defensive tool consideration. While they offer more raw energy than handguns, that doesn’t come at the cost of over-penetration of walls and other household obstacles.

Even with full metal jacket ammunition, those light rifle bullets tend to penetrate common objects less than pistol projectiles. Perhaps the biggest deciding factor is the size and two-hand use requirement. A simple sling can go a long way to mitigate that issue as it functions as a “rifle holster.” So, don’t write off an AR as your home defense solution because you think it might be “too much.”