Using .300 Blackout for Home Defense

posted on May 26, 2017

The .300 Blackout round has long been considered a mainstay in the world of tactical guns, gear and ammo. I'm not tactical. I never served in the military, I don't own any clothing in any of the current military camouflage styles, and I have exactly one piece of gear (a backpack) with MOLLE webbing on it.

However, like many people, I have a safe room in my home to use as a last redoubt for my family in case of a home invasion or similar horrible situation. Inside that safe room, among other things like a flashlight and first kit, I have a long gun for the defense of my family. For years, I've relied on a tried-and-true Mossberg 500 pump-action shotgun as my safe room gun. I've upgraded mine with a sidesaddle carrier on the receiver that holds six extra shells and a SureFire light to verify what's in front of the muzzle of my gun. However, I started to consider .300 Blackout as another option for home defense.

I initially went with a pump-action shotgun for its ease of use and devastating firepower. With 8+1 rounds of buckshot ready to roll, it's a formidable defensive tool, and I rest a little easier at night knowing it's nearby. However, a pump-action shotgun is not without some drawbacks when it comes to defensive uses.

First is the limited ammunition capacity and slow reloading time of a pump-action gun compared to an AR-platform gun chambered in .300 Blackout. Yes, with practice, I could ramp up my reloading times to the lightning-fast speeds that cowboy action shooters use to reload their shotguns, however, my training time is limited, and I'm concentrating right now on working with my concealed-carry pistol, not my shotgun. Also, pump-action shotgun needs two hands to use effectively, and I'd like something that would work if one hand is otherwise occupied or has been injured and is no longer useful.

Then there's the noise. A gun going off inside a small room, like my safe room, is loud. Very loud. Loud enough to cause permanent hearing loss in myself and my family. I own several pairs of electronic ear muffs that work wonderfully at blocking out harmful levels of sound, but donning earmuffs is one more thing to worry about on the way to safety, and I want as few impediments as possible between myself and an effective way to protect my family from harm.

In addition to this, I've been intrigued by the potential of the pistol-caliber carbine as defensive tool that brings a little more to the fight than just your defensive pistol. For years, military has used intermediate weapons like the M1 Carbine, Heckler & Koch MP7 and FN America P90 as something that offers more punch than a pistol, but has less weight and bulk than a rifle. I wanted those same advantages in my home-defense gun, which led me to choosing an AR-15 pistol in .300 Blackout as a replacement for my pump-action shotgun.

An AR-15 pistol in .300 Blackout, especially with subsonic loads, solves a lot of those issues. Because it was designed from the start to be suppressed, subsonic loads in this caliber pack a wallop but still run smoothly, reliably and are lot easier on the ears when suppressed. An AR-15 pistol gives me a smaller gun than a full-sized AR, and with 30 rounds of 220-grain subsonic ammunition in a magazine, I am giving up nothing when it comes to firepower, compared to my shotgun. Also, because the ammunition magazine is closer to the center of gravity in an AR pistol than it is in a tube-fed shotgun, the AR is easier to handle inside of tight spaces like the average American home, and as a bonus, the gun will still cycle and shoot while only using one hand to operate it.

The round uses the same magazines as 5.56 NATO / .223 Rem., and I've seen pictures in social media of people who have destroyed their guns by unintentionally stuffing a magazine filled with .300 Blackout into a gun that shoots 5.56 NATO, resulting in some spectacular (and dangerous) explosive disassemblies of their guns. Paying close attention to what rounds are loaded into your magazine before you insert into your gun is always the best way to avoid such mishaps, and I've chosen to add in an extra layer of safety by using only Lancer AR magazines with my .300 Blackout gun. The transparent sides of the Lancer magazine allow me to see what's inside before I slide it into the magwell, and an extra layer of caution is never a bad thing when it comes to avoiding an expensive (and dangerous) mistake, like loading the wrong ammunition in your gun.

I built my .300 Blackout pistol using an Anderson Manufacturing lower, a Hardened Arms upper with a 10.5-inch free-floating barrel and a KAK Shockwave Stabilizer brace. I added in some other items based on my personal preferences, like a soft Ergo grip and an older Insight light that I'll be swapping out for a Streamlight ProTac 2 in the near future. Also, because I'm cross-eye dominant and shoot long guns left-handed, I added an ambidextrous safety and ambidextrous charging handle for ease of using the gun with my left hand. As this gun will ultimately have a suppressor on it, the muzzle device on the gun (for now) is a standard A2 muzzle brake, which will allow me to easily thread on my suppressor when my tax stamp is processed and my suppressor arrives.

For now, though, the gun resides in my safe room, ready to defend my family's life if needed, and I chose .300 Blackout not because not because it was the ultimate military cartridge, but because it was the best solution out there for keeping myself and my family safe.


Camfour Custom Springfield Armory 1911
Camfour Custom Springfield Armory 1911

First Look: Camfour Custom Springfield Armory 1911 Garrison Pistol

A case hardened slide and frame is just the beginning. 

First Look: HYDRA Survival Package

One gun, four calibers, one case.

Review: Garmin Xero C1 Pro Chronograph

Every once and a while, something really is game-changing.

New Rifle Suppressors for 2024

The latest products to tame the roar of your rifle.

First Look: Field & Range Cases from Federal Ammunition

Rugged gun cases for the rugged outdoors.

Concealed Carry Clothing With Style

How to dress to the nines while carrying a nine. Or a forty. Or a forty-five.


Get the best of Shooting Illustrated delivered to your inbox.