If you want to start an argument, then start telling everyone which handgun caliber they should use. Most gun owners have strong opinions about their preferred caliber. Unfortunately these opinions generally aren’t based on facts. In this article, we will review some excellent data on seven different handgun calibers, and over 30 different rounds, to examine the effects of handgun penetration through walls. I will also provide some ballistics gel data so we can pick the best rounds for self defense.
Before we get into the nitty gritty of this article, I want to cover some expectations. First, I’m not telling you what you should or shouldn’t carry, or use for home defense. That’s your decision, and you need to determine what’s best for your individual circumstances. Hell, some of the ammo we’re talking about might not even be legal to own in your state (looking at you New Jersey).
I’m attempting to narrow down some key parameters that will allow you to be more successful in a home or self defense situation. For this article we are going to narrow down our considerations for handgun penetration through walls. If you want data on how likely handguns are to stop an attacker, then you need to check out this article where I review data on over 1800 shootings. Here’s the bottom line up front.
Bottom Line: Handgun Penetration Through Walls
- .22-.38 Caliber rounds penetrate roughly the same through dry wall
- Normal 9mm, .357, and 45 ACP rounds will generally penetrate around 10 inches of dry wall.
- Pine board and dry wall are not cover
- Interior wall penetration shouldn’t be the prime consideration for self defense rounds
Handgun Penetration Through Walls: The Data Set
If you’ve read any of my other analysis articles, you’ll know that I like to find good data sets, and combine them so we can make informed decisions. For this article, much of this data comes from GunTests.com. They tested over 30 different rounds by measuring their velocity, and shooting them through dry wall, and pine board, simulating a normal interior wall. They measured the inches they penetrated, and gave some recommendations on which rounds “over penetrate.”
I’ve also utilized other data, from LuckyGunner.com and their extensive library of ballistics gel tests. I really recommend you head over and check their site out. It’s very thorough, and easy to understand. While they focus on ballistics gel tests, and don’t have data on handgun penetration through walls, they have many more calibers and rounds tested.
Handgun Penetration Through Walls: Results
Because there are so many calibers and rounds tested, I’m splitting the data up into small, and large caliber handguns. I’m also going to split the data up into handgun penetration through drywall, and handgun penetration through pine board.
Later on in the article, I’m going to take a look at the penetration data, and cross reference it with ballistics gel data, to give you some great self defense picks. These picks shouldn’t over penetrate interior walls, but will perform well against human attackers.
Each of these charts is the same, but I want to specify how you should read them. On the vertical Y axis of each chart is inches of penetration through whatever medium the chart shows. Each column is a separate round, labeled at the bottom with bullet weight. At the top of each column is the velocity of the round measured in feet per second. Here’s the full data used to make the graphs. Yellow highlighted items are cross referenced with ballistic gel data later on.
Handgun Penetration Through Walls: Small Caliber Handguns (.22-.38)
When we consider small caliber handgun penetration through walls, there is quite a variety of depth. The .38 caliber special glass safety slug penetrates the least, at just over 4 inches, where as the .22 magnum rounds penetrated around 12 inches. Most of these rounds averaged between 6-8 inches of penetration through dry wall.
If we consider their performance through pine board, the penetration numbers look a lot different. The standard 22 LR rounds penetrate 2 inches deep, which would be through the depth of a 2×4, as they aren’t truly 2 inches thick. The 158 grain Winchester in .38 penetrated around 9 inches, with most rounds in this category averaging 5-6 inches of pine board penetration.
Next, let’s take a look at this same data with large caliber handgun rounds. Remember, the charts will be read the same way, and have all the same data on them.
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Handgun Penetration Through Walls: Large Caliber Handguns (9mm-.45)
Right off the bat, we notice that velocities are higher across the board, as is bullet weight. The speciality rounds are still penetrating around 6 inches of dry wall, and the more traditional bullets are averaging between 10-12 inches of dry wall penetration. Keep in mind, 12 inches of dry wall sheeting is 12 walls worth of dry wall. This means that if the bullet hit nothing more serious than drywall, it would go through at least 6 rooms!
Large caliber handgun rounds also penetrate through pine board between 8-12 inches and are averaging around 6-8 inches for normal, non speciality rounds. Remember that a bullet going through 12 inches of pine board is roughly equivalent to it penetrating 3 studs, shot edgewise. That’s a lot of energy!
If we based our self defense ammunition selection only off of handgun penetration through walls, we might be forced to choose some odd safety slug rounds, or a .22. Needless to say, those would not perform well against a human attacker. Let’s take a look at some ballistics gel data to see where that takes us.
Handgun Penetration Through Walls and Ballistic Gel Tests
Ballistics gel tests are a good approximation of a bullets performance when shot into a human body. The blocks themselves are calibrated to an average density of the human body. While there is no average place to get shot, and structures like bones will cause rounds to do unpredictable things, it’s still a good standardized medium to test with.
Handgun Penetration FBI Protocols On Human Attackers
The FBI recommends that bullets penetrate through 12-18 inches of calibrated ballistics gelatin. Lucky Gunner, tested these rounds through gelatin and a clothing layer, placed in front of the block. This is a reasonable testing protocol, which would mimic a torso shot through something like denim or a heavy jacket. Let’s see how our rounds performed.
Top Picks By Caliber For Self Defense
For this portion of the article, I chose four different rounds from four different calibers. I did this to see what comparisons we can make across caliber. I did not include anything smaller than .38 caliber, as the data on its efficacy from my 1800 shootings analysis leads me to believe that it isn’t well suited for self defense.
Yes, yes I know you heard a story about some guy who shot a bear with a .22 magnum, but anecdotes are not data, and on average a bigger bullet will generally do better. Don’t get too excited 1911 bros, I have charts.
This chart is slightly different, as I’ve added two data labels to each column. I’ve included the velocity in FPS, and the specific penetration data for each round, measured in inches. At first glance, there isn’t much of a difference between these rounds, but I’ve included much more data in the section for each round including: expansion diameter, and performance against its peers.
38 Special Round
This round is the Winchester Super-X LSWCHP out of a 2 inch test barrel. Lucky Gunner determined that the first shot penetrated 15.8 inches, and after five shots, the mean penetration was 18 inches. Both of these penetration statistics fall within the FBI recommended 12-18 inches.
They also determined that the hollow point expanded to an average diameter of .36 inches, basically no expansion at all. While lack of expansion might not be great, it’s more important that the bullet penetrates to the right depth. After all, the goal is to reach vital organs.
9mm Round
The 9mm round is the 147 grain Hydra-Shok JHP by Federal. It penetrates 17.8 inches on first shot, and has a five shot average of 17.7 inches. This is interesting because most bullets they test gradually penetrate further as more rounds are fired. This shows that that hollow point is reliably using all of its energy in the gel.
9mm Ammo – 147 gr Hydra Shok JHP – Federal Ammunition – 20 Rounds
Just like the .38 special round, this round showed no real expansion. Once fired it expanded to .36 inches from a starting diameter of .35 inches. Remember expansion is nice, but depth is probably a more important factor with handgun rounds.
.357 Magnum Round
This round is the .357 Mag – 125 gr Remington Golden Saber. It penetrated to 19.4 inches on first shot and averaged 18.7 inches after 5 shots. This places it right at the far edge of the FBI protocol. You can expect that there would be a small amount of over penetration in smaller targets.
357 Mag Ammo For Sale – 125 gr JHP Remington Golden Saber 357 Magnum Ammunition In Stock
This round showed a tremendous amount of expansion. After being fired, it expanded to .615 inches, or roughly twice its original diameter. This is interesting, because the round penetrates a lot, and expands the most compared to the previous round. This is because the bullet weighs less and is cooking along at 1090 feet per second.
45 ACP Round
Now get ready for some two World Wars comments after this one. This round, the .45 ACP Hornady Custom XTP performed well. When you watch the video you can actually see some temporary cavitation effect as it enters the gel. Normally you only get this effect with fast moving rifle rounds.
45 ACP Defense Ammo For Sale – 230 gr +P JHP XTP Hornady Ammunition In Stock – 20 Rounds
The first shot penetrated to 17.7 inches, and the five shot group averaged 18.6 inches. This bullet expanded to .61 inches, which is pretty good. There’s also another benefit. If you click on the link, you’ll find that this ammo is in stock as of this writing, which is definitely not the norm!
While you may think that this test indicates that the .357 magnum and the 45 ACP are the only good rounds for self defense, we need to consider the handgun penetration through walls. Let’s take a look at the original chart.
The 45 ACP has the most penetration on both dry wall and pine board. The 9mm and .357 penetrate about the same, and the .38 penetrates the least. The question we need to consider is, does this data alone mean that we need to pick these rounds?
Limitations and Practical Considerations
The biggest thing to consider is what handguns are available to shoot these rounds. Both the .38 and 357 magnum are almost exclusively revolver rounds. There is nothing wrong with a revolver, but they do have limited capacity. That can be a severe problem when we look at real world shooting data.
This chart, from the linked article, shows that for .38 and 357 magnum you are looking at two rounds striking the assailant before they are incapacitated. I can also tell you that your accuracy, in a life threatening situation, is likely to drop by one half to two thirds.
You run a substantial risk of running out of rounds before you can land two in a fatal area, during a self defense encounter. If you spend the time to maintain a high level of proficiency, I would agree that these rounds can be perfectly capable in the right hands.
You’re more likely to find success with 9mm or 45 ACP. In the 9mm, you have a good cartridge with moderate handgun penetration through walls, and solid performance against humans. You also have a low recoiling round, that can be found in many full sized handguns. If you’ve spent anytime shooting, you’ll know that full sized handguns with low recoil, are the easiest to control.
The 45 ACP probably does over penetrate in structures. If you live in an apartment building, then this may be a big consideration, depending on where your fire walls are, and the layout of your building. If you can control this round well, and you don’t mind somewhat limited magazine capacity, this would be a good choice, provided you aren’t worried about handgun penetration through walls.
Here are some links to good handguns to choose from.
Final Thoughts
This has been a long article so let’s summarize a few key points. Most normal handgun rounds will penetrate through several walls in normal interior structures. Larger heavier bullets will penetrate further. While handgun penetration through walls certainly is a consideration, we must first look at the effect of the round against a human target.
As long as the round penetrates through 12-18 inches of gel, and doesn’t over penetrate through walls, it will be sufficient for self defense use. You then need to select a firearm that you shoot well, and has adequate magazine capacity. Operate under the expectation that you’ll likely have some misses in a self defense shooting.
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I have seen several articles this year about bullets passing through walls and hitting children who were asleep in their bed. What building materials would be needed for exterior home walls to prevent bullet penetration by the most powerful of common handgun calibers?
Generally speaking brick or concrete will be your best bet.
So, a regular brick veneer on the front of a house should give protection from random drive-by shooters like Dreasjon ‘Sean’ Reed? Thanks you.
Provided they are normal bricks most likely. Some veneers are extremely thin and wouldn’t provide any protection.
I’m a little late here, but am I understanding the last chart correctly? The quickest way to incapacitate is with a shotgun, not surprising.
But the second quickest way? A .22!? Really? Is that because of the lack of recoil?
Then a rifle, not surprising.
Then a .32?
The slowest to incapacitate are the 9mm and the .40? 4th slowest is .45? Again, because of recoil?
It sounds like many are arming themselves with weapons they can’t control well.
There are people who like guns, and then there are people who train proficiently with their guns. Maybe the second group are arming themselves with calibers they can handle in a crisis, like .22s and .32s.
Remember some of those stats aren’t physically incapacitated. Some of them mean only that the person stopped their violent action or fled.
And thanks for the work.
Extremely high learning experience for me. Thanks for the great article and the effort to provide it.