5.56 vs. Drywall: Is Your Home Defense Gun Dangerous?

By Paul Carlson

I got into shooting for self-defense. Sure, shooting is fun, but personal protection is and has always been my top priority when it comes to shooting.

One of my recent topics of inquiry was the self-defense performance of 5.56 ammo from a short barrel rifle inside a home. I wanted to test common AR-15 ammo and see if overpenetration was a legitimate concern in a home defense situation.

While I’ve seen what happens when a .223 Rem or 5.56 NATO round hits bare drywall from a 16″ barrel, I’ve seen little testing beyond that.

In this ammunition test, I simulate a round that went through an attacker and into drywall. I wanted to test if the bullets would penetrate a common interior wall? If so, does the projectile pose a risk to anyone beyond?

I’m going to take you on my journey of discovery on this topic with me today in the video above and the article that continues below. The question I am going to ask is, will a .223/5.56 round from a short barrel rifle pose a risk to a loved one after penetrating both an attacker and an interior wall?

Ammo for the Short Barrel Rifle

In the past year, I made the transition from a carbine-length AR to a Springfield Armory SAINT Victor SBR with a 11.5″ barrel. The size of this gun made it perfect for all of my family members to shoot should any of them need to use it in a home invasion.

Of course, I dove into getting that rifle ready to rock.

I assumed that the defensive ammo I’d been using in my full-size AR was going to be the right choice for the SAINT Victor SBR. Maybe it was the right choice, but maybe it wasn’t. That’s the problem. I’d never really done the work to decide what the right ammo was for my rifle.

I reached out to friends in the industry and started conversations. Eventually, those conversations led to some options that Hornady has available for 5.56mm.

I picked up three different Hornady loads that people might select for home defense. I took those rounds to the range with my SAINT Victor SBR and tested them with some gel. I wanted to get answers for myself!

Thoughts on Home Defense

Home defense amounts to more than just ammunition.

Having a solid plan is the foundation of any success. I can’t tell you what your plan should be, but mine includes an alarm system, reinforced doors, secured windows, a home defense kit and more.

If you keep a firearm, you should consider how to store your home defense gun and the most likely places where you may be forced to shoot your gun. Some people call these “sectors of fire,” which is simply a way to catalog them in your mind.

Where are your sectors of fire? Do those sectors of fire endanger those that you love? I think you get the idea of what I’m asking here.

Home defense should be set up to deter an invader. Should you need to fire, know the angles where you may have to shoot so that your family will not be harmed by the gunfire that could ensue.

When I think about defensive ammo, I wonder how far and how deep those rounds are going to go. This is not something I can gamble on.

Testing Parameters

In order to pick the right ammunition for the AR SBR in home defense, I wanted to shoot something that simulated that worst-case scenario: dealing with a deadly threat with family members in the area. I want a cartridge that stays in the threat and, if not, tends to underpenetrate should it strike a second soft target.

I set up a 6″x6″x16″ block of Clear Ballistics Gel sideways. I know that the AR is going to push through that 6″ cross-section of gel. I then set up two sheets of drywall fastened to 2×4 spacers to simulate an interior wall. Finally, I arranged another Clear Ballistics FBI Block to receive the round after it left the wall.

The whole idea is to create a model that can compare different rounds and the penetration they might have if they leave a bad guy and continue on.

I don’t think I found any definite answers (do we ever?), but I did discover a lot of new questions to be asking.

Be aware: I got pretty excited in the video and declared a winner. After more consideration, I’m not so sure … . Again, this is an exercise to start understanding what questions I should be asking.

The Results

The final results show that the engineers at Hornady know how to design a round to achieve specific objectives when it comes to terminal ballistics.

The 55-gr. Frontier ammo from Hornady is a no-frills FMJ round. It is a .223 and performed exactly how I expected it to.

The Frontier easily penetrated the 6″ block and started tumbling. It proceeded through the two sheets of drywall and into the 16” block. The round continued to tumble and then exited the block about 10″ farther along.

Of course, that slug is gone, but our original test round stayed in the block at around the 10″ mark as well. We used that bullet for our mass and expansion.

Next up was Hornady Critical Defense, part of a large line of ammo targeted to customers looking for a round that will perform well in defensive scenarios. The polymer tip helps the round to expand reliably when it needs to penetrate the attacker’s clothing. This 55-gr. .223 load isn’t designed to be a deep penetrator — especially when barriers are involved.

Our results were impressive. After defeating the dry wall layers, the Critical Defense slug came to rest just a bit over 3″ into the 16″ block behind the simulated wall. By far, the Critical Defense penetrated the least in our test.

Last up was Hornady Black HD SBR ammo. This round stood apart from the other rounds we tested in three ways. First off, this was the heavyweight in the test. While the other rounds were both 55-gr. rounds, this load weighed in at 75 grains. I expected this to change the performance of the bullet significantly and lead to deeper penetration.

The BLACK HD SBR features the InterLock bullet technology developed by Hornady. This process approximates a bonded bullet by pressing the jacket and core together with a crimp cannelure into a ring in the lead core. This results in deeper penetration and greater mass retention.

Finally, the SBR in the load’s name stands for “Short Barreled Rifle.” This round is designed to perform at the appropriate velocity for an SBR or AR pistol. The idea is that the load is tuned to expand optimally from the shorter barrel of the SBR or pistol.

The BLACK HD SBR penetrated a solid 10″ into the 16″ block, maintained its mass, and expanded impressively.

	Frontier	Critical Defense	BLACK HD SBR
Caliber	.223 Rem	.223 Rem	5.56 NATO
Bullet	55-gr. FMJ	55-gr. FTX	75-gr. Interlock
Penetration	10″	3-4″	10″
Expansion	.256″ (+14.2%)	.367″ (+63%)	.523″ (+133%)
Mass Retention	37.6 grains  (68%)	29.0 grains  (52%)	71.6 grains  (95%)

Final Thoughts

I am very pleased with how this project has come along. As I mentioned previously, these kinds of investigations often lead to more questions than answers. In this case however, the experience has helped me to draw some conclusions.

First off my decision to select an AR, specifically the Springfield SAINT Victor SBR, has been confirmed. Although there is no perfect solution, this SBR fits my needs well. My whole family can run the gun and the terminal ballistics of the AR SBR are right where I want them to be. I am convinced that the AR, when used with quality ammunition, reduces the risk of over penetration significantly. I do not have the same confidence with handgun or shotgun rounds.

Second, I have been heading down the right path in selecting defensive ammunition for my AR for home defense. Certainly 55-gr.  FMJ can do solid work, but I’m convinced that defensive rounds offer serious advantages over ball projectiles.

Next, I am very pleased with the terminal ballistics that the rounds from Hornady displayed in our test. I am left with two great choices in defensive ammunition. The bonded Hornady Black HD SBR is going to penetrate regardless of intermediate barriers and expand reliably, while the critical defense is a great choice for situations where overpenetration is a critical issue.

Finally, I am reminded how important our home defense tactics are. Yup, we should select the best hardware combination. That won’t be a guarantee and no amount of penetration is okay when we are talking about someone we love. So, make a plan, make it a good one and get your hits.

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Featured in this video

556^NATO

SAINT® Victor SBR

Hornady 5.56 75 gr. Interlock HD SBR BLACK

Hornady .223 55 gr. FMJ Frontier

Hornady .223 55 gr. FTX Critical Defense

Clear Ballistics 10% Ballistic Gelatin FBI Block