Safety and Training

Bullet Penetration in Home Environments

Bullet path through a wood block

When choosing a home defense handgun, rifle, or shotgun, the gauge, caliber, and load are important considerations. If you are in a crowded area, this is important. If you reside in a rural area or the home is isolated, penetration of building material doesn’t mean as much.

2x4 stud with 9mm and .45 ACP bullet holes
The .45 and 9mm exited, but in this case the 40-grain High Velocity .22 turned and came to a stop.

Or does it? There may be family members in other parts of the home, and the shots cannot be called back once they are sent out.

The primary goal of a personal defense load is to penetrate the adversary’s body, do damage to vital organs, and cause a shutdown of the pressurized system. Only blood loss will cause this shutdown. The responsibility of the home defender is to strike the target.

Firing when you do not have a reasonable expectation of hitting the target isn’t a responsible action. Being human, you may miss, and you should know what to expect when a bullet connects with common building materials.

There is an interest expressed by defensive shooters in the use of cover, and I felt I should take that track as well in my testing.

What types of building material will give the homeowner cover if they are under fire? After all, bullets go both ways. Hardening a home against gunfire is a daunting proposition. If you elect to pour concrete between the walls, be certain the foundation will hold the weight.

Since abandoned homes in a safe area that the owner is willing to allow me to shoot to pieces are rare, I constructed simulated walls and fabricated test objects. Next I fired a few hundred rounds of ammunition and destroyed a truckload of structures.

Drywall from a home with several bullet holes
Wallboard doesn’t stop most projectiles.

In the end, I discovered loads that are very attractive choices for home defense. You cannot sacrifice penetration by choosing loads that blow up on heavy leather jackets or fail to penetrate to the vitals, but neither do you wish to use a Magnum hunting load in the handgun.

The primary focus was on the handgun, as the handgun is always with us, but I studied rifle and shotgun performance. The problem of overpenetration in the home or apartment has been discussed many times. The fear of a bullet carrying far past the area of a gun battle is real.

Wounds received by innocent persons happening to be in the wrong place at the wrong time are not uncommon. However, most of these occur in the open or on the street and are a result of missed shots rather than overpenetration. The great majority is the result of actions by our protein-fed ex-con criminal class rather than honest citizens. Incidents involving homeowners firing through walls or a bullet exiting the home are less common.

The majority of armed citizens are mature, conscientious individuals. I looked at the whole picture and tested ammunition from several angles. Homes differ in construction, and at best a general understanding of home penetration parameters was gained. Responsibility for every round fired is a concern and safety from a bad guy’s bullet another.

.223 Remington bullet fragments
Lightweight .223 bullets stopped short in wallboard, and many fragmented.

The first solution to the danger of an overpenetrating bullet exiting a home is to hit what you are shooting at, as I keep repeating. Carefully place a hollowpoint bullet into the assailant to let it expand properly and there will be no overpenetration problem. Know the distance between one occupied structure and the other.

Since we usually fire at an angle slightly up or down and seldom perpendicular to the target, the chances are the bullet will come to rest in something before it reaches an occupied home. A studio apartment with thin walls is another matter.

Hopefully, the burglar will present himself to your view and enfilade fire will get his attention. If he is in defilade, however, and under cover, you may need the ability to penetrate cover rather than limiting penetration.

There have been ridiculous cinema depictions of felons using a chair or mattress for cover. Bullets zip through these constructs, but some furniture may be heavy enough to turn a bullet. Will you be engaging in wall stitching in the home? Are there bullets that expand well in a body and stop short in home material?

Fiocchi 40-grain V-Max ammunition box
The Fiocchi 40-grain V-Max is an inoffensive home defense round.

Many high-velocity hollowpoint bullets will expand in the body, true, but when they hit the wall the bullet nose plugs and they penetrate like a full-metal-jacket bullet.

I noted that every test program in the popular press was inconsistent, with every author having a different idea, including some of the work I have done—after all, I learn things as I go along. One of the considerations never mentioned in the popular press is the existence of firewalls between walls in apartment complexes. (Older buildings may not have them, but let’s hope you live in a dwelling with firewalls.)

Stairwells and common hallways are an important consideration for the defensive handgunner. Another consideration is the difference between high-speed, light bullets and heavy, low-speed bullets. Drag is a slowing force that seems to work more quickly on fast-moving, light bullets. Heavy bullets, even when moving slower than light bullets, tend to penetrate more, as is the case with the 147-grain, 1,000-feet-per-second 9mm versus the 115-grain, 1,200 fps 9mm and the 230-grain, 850 fps .45 versus the 185-grain, 1,100 fps .45.

I tested a representative sample of handgun rounds against materials including pine board, drywall, cinderblock, and brick and added whatever I could come up with. The information obtained is interesting.

Hardened board with .45 caliber bullet hole
The author shot this old hardened board with a .45, left; 9mm, center; and .22LR, right.

Common sense tells us that a loading by one maker or the other will probably perform similarly to the test load in penetration if not in expansion, such as 115 grains at 1,200 fps in 9mm. Since the nose closes up and the bullet penetrates, a presumption is often made that only velocity and weight really matter, not bullet design. The same goes for 9mm full metal jacket or .45 ACP hardball, with one brand similar to the other.

This is actually true when it comes to FMJ loads but not true with JHP loads. A wide-mouth hollow-point such as the 115-grain JHP used in Buffalo Bore’s +P 9mm load breaks up rather quickly when fired against cinder block and doesn’t penetrate as much in wood as the slightly different Buffalo Bore +P+ load. The +P+ load uses a bonded design. The bullet stays together, as is the intent.

With the development in bullet technology during the past decade or so seeming to focus on bonded-core bullets, we need to carefully appraise our choices. Do we really need a bullet with high penetration against felons behind cover? Are the felons likely to be bundled in heavy clothing?

Bob Campbell shooting a 12 gauge shotgun at the shooting range
The 12-gauge shotgun is a formidable weapon that destroys home material easily.

Bullets with less gelatin penetration are less offensive in home penetration. I stand by the need for greater penetration in defense loads—at least on the level of 10 to 12 inches in water or gelatin—but it is clear that bonded bullets are designed for penetration of sheetmetal and window glass and perform as designed. Whether this is desirable is up to the homeowner.

In this test, the exactness of what we accomplished is respectable, but the great, broad, general conclusions of the test are also important. Judging by my experience in gelatin and water testing, loads that penetrate 12 inches of gelatin or a similar amount of water will not have sufficient energy to be dangerous and penetrate wall material once they penetrate a felon’s body—after all, they should be expanded. The real difference in safety is hitting the target.

Never use roundnose lead or full-metal-jacketed bullets for home defense. While the .45 ACP 230-grain FMJ is an effective anti-personnel load, a JHP bullet is more effective. I did not test ricochet, for safety’s sake, and neither should you. But among the few scares in the program was when RNL bullets bounced a bit when fired into hard wood. Even the .45 ACP, let alone the .38 RNL, will ricochet off a hard gradient.

hardened board shot with a .45 ACP 230-grain FMJ loading
We shot this old hardened board with the .45 ACP 230-grain FMJ loading.

Our Results

At one time, pine boards were the testing material for handgun bullets. After all, with RNL or FP lead bullets the FMJ expansion wasn’t a concern but power and penetration were. Around 1900 or so, pine board testing was commonly used by ammunition companies to illustrate the effectiveness of a handgun loading. Today, we might test pine boards in order to understand wall stud vulnerability to bullets. However, also understand that the studs in a wall will be facing rather than lengthwise, but just the same, this test is valid depending upon the bullet angle.

For our tests purposes, the pine boards were set up an inch apart to allow parts of the boards to be separated from the bullet as it flew through the boards. All boards are not the same, and a quarter-sawed board will be more dense. A quarter-sawn board is quartered lengthwise, and there are wedges at right angles to the center of the original board. So—different boards, different results.

Another unscientific but interesting test of hardened four-inch-thick boards was conducted. In this case, the .45 ACP loads—mostly 230-grain ball—not only fully penetrated, it was obvious that they were pushing a large wound cavity. There was actually a recognizable lengthening of the cavity as the .45 ACP bullet pushed through the board.

Brick Constructs

Bricks are found in a single layer attached to the outside wall of a frame building. Next are wall studs, plywood, and insulation. I shot bricks stacked in groups or four or more. In a true home environment, the shot is coming from the inside out in the case of a missed shot and would hit the wallboard first. In a drive-by, bricks are hit first. When bricks are in sections, mortar holds them together and the support of the structure keeps them resilient. In firing, a pockmark was seen on the bricks and nothing more with the calibers below .38 Special.

small well house
This small well house was purchased at a yard sale. The construction is similar to home material, and the boards were treated to resist the elements.

Beginning with the .38, damage began to be evident. The 9mm and .45 ACP bullets damaged the bricks but hardly enough to go through. After two to four shots, the bricks were cracked. The .357 Magnum revolver and the .223 Remington rifle were very similar, bringing into focus the often-quoted remarks of early users of the Magnum: “It is like having a rifle on the hip.” The .357 and the .223 each took a large chunk out of the brick and often broke it with a single shot. We found that one to two rounds in the same spot often broke up the brick and crumbled it.

In the case of cinder blocks, the .45 ACP JHP just made a pockmark, and part of the bullet penetrated on the first shot. The fast-stepping 9mm was much the same. The .357 Magnum 110-grain loads did no more. The 1,400-fps .357 Magnum struck the block three or four times without great effect.

The 158-grain JHP .357 Magnum load made a large cavity in the block with the first shot and an opening into the hollow between the two sides of the block with the second shot, sometimes with the first shot. The third shot with the Magnum shattered the cinder block.

A slow-moving 158-grain .38 Special SWC at 850 fps did more damage than the 110-grain .357 Magnum. The 230-grain FMJ .45 broke up the blocks with very few shots. Moving to the 12-gauge shotgun, double-ought buckshot produced spalls (pockmarks) without penetration and bounced like mad in some cases.

We took at least a 50-foot setback when testing and were glad we did when this unexpected event occurred with buckshot. The buckshot balls flattened on cinderblocks and bounced back 10 to 12 feet. This would not be the load of choice in a crowded environment with a cinderblock wall. You could easily shoot a felon and yourself with one shot. Shotgun slugs demolished cinderblocks with a single shot.

The next step was wallboard penetration. It should be no surprise that bullets and buckshot go through wallboard—it’s just paper and clay. As one of the raters noted, there is no magic bullet that will not penetrate in the home and relieve you of the responsibility of aiming straight and not engaging in spray-and-pray. Every shot must be carefully aimed.

Just the same the results are interesting, and it is obvious that some cartridges are better than others. We built a construct of wallboard with a total of 12 boards. They were not complete walls, but in some cases simply 12×12 sections nailed to boards—12 wallboards, six walls. Then we had to rebuild them several times. This comes out to six walls with one board in and one board out. The results are interesting.

Some Individual Loads

Man firing a handgun at an outdoor range
A lot of testing goes into this type of research.

.223 rifle

During our .223 ammunition tests we found that many .223 rifle rounds are best suited for varmints. They stand an excellent chance of breaking up on light cover, a belt buckle, or heavy clothing. So, we are beginning with a round that needs a bullet of 50 grains or more to be effective in personal defense.

While the .223 may be very effective in home defense, the question of muzzle blast is harrowing. The blast (the .357 Magnum is another offensive caliber) is potentially deafening, with permanent effect on our hearing. If you have the carbine and your Wolf Ears at home ready, you are way ahead of the game, but few will do this.

The .223 loads bear special attention.

Fiocchi 40-grain V-Max

This load began to fragment in the first wall of the wallboard testing. When the second section of the first wall was penetrated, the bullet was obviously fragmenting. Some pieces made the second wall, but none fully penetrated the fourth board. Most of the 10 rounds fired stopped in the third board. This is a good, safe bullet for interior use, but it may not have sufficient penetration for defense.

Black Hills 55-grain JSP

This load surprised us. We were expecting more, but it penetrated the third wall—six sheets—and fell across the next wall in fragments. That is still three walls but less penetration than some of the pistol rounds.

Black Hills 60-grain JSP

This is a highly recommended service load. This load ran right through all 12 sections. Since the 55-gr. JSP load was a good personal defense load and penetrates less in wallboard, it would be the recommended loading.


12 Gauge Shotgun

If anyone doubts how awesome the shotgun really is, this test is an eye-opener. Wallboard was blasted to pieces by most of the loads tested. Recoil is there, but the shotgun has great wound potential. Some thought should be given to this gauge and the loads. The buckshot loads potentially go through a lot of home material. On the upside, few antagonists struck with a load of buckshot will need a second hit.

Winchester 7½ birdshot

I have never tested birdshot for personal defense, so I had to do a few runs on water jugs to be able to intelligently comment on this loading. It has been recommended for home defense but obviously without a lot of testing. The result was poor in water testing—4 to 6 inches of penetration with only one or two pellets exiting the first water jug. This would be perhaps 4 inches of penetration in gelatin and not enough penetration for personal defense. In wallboard, this light shot penetrated two boards (one wall) and peppered the third board.

Winchester Reduced Recoil 00 Buckshot

This load penetrated five walls, 10 boards on demand.

Winchester #4 Buck

This load penetrated seven to eight boards and usually peppered the ninth board. It is a reasonable choice but an inferior answer to 00 Buckshot.

Federal 12-gauge TruBall One-Ounce Slug

This penetrated all 12 boards easily.

Bullet Penetration in Home Environments — Summary

The .223 isn’t offensive for home defense, no questions there. With the proper loading, the .223 may just be the ideal choice. Most handgun loads are similar in performance. The fast-opening JHP loads that demonstrate gelatin performance of good expansion and penetration of 12 inches are best for home defense overall. Loads on the long end of penetration will also penetrate on the long end in home materials.

The results of this tests show that 9mm, .357 Magnum, and .45 ACP JHP bullets are probably the best choices for home defense. FMJ and heavy hunting loads are overpenetrative for home defense use. In long guns, the .223 rifle is superior to the shotgun as far as safety goes. Still, the shotgun offers a devastating wound for those who have the proper scenario for its use.

Do you have a favorite load for home defense? What penetration testing have you done? Share your answers in the comment section.

The Mission of Cheaper Than Dirt!'s blog. "The Shooter's Log", is to provide information - not opinions - to our customers and the shooting community. We want you, our readers, to be able to make informed decicions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (21)

  1. Hello,
    I toughly enjoyed this article.
    The only thing I didn’t like was the use of pictures of old rotten wood.

  2. I don’t see any testing or results on a lowly .22 LR. This is the most common pistol or rifle cartridge in America, and very common for home defense. Used properly, being able to hit a target with low recoil repeat-ability is more important than big guns that are hard to hold down on target, especially for women.

  3. What about specialty rounds:
    Hollow point with sabot
    Glazer Safety slugs
    How do these stand up as they are touted as anti personnel rounds

  4. Hello,
    Have you ever tried or looked into Lehigh Defense’s ‘Extreme Defense’ rounds.
    Solves many problems.

  5. Great article! Did you any testing with frangible rounds. I use these in my home defense pistols because overpenetraion is a very real concern for me. However, I have no appreciation for their effectiveness in soft tissue or their overall stopping power.

  6. A test with a .410 shotgun might be interesting.. In your test a 12 gauge was low on the safety list.. A .410 would likely rise on the safety depending on slug or self defense load.
    Serious damage to a bad guy, but less potential of penetrating damage on a missed shot.

  7. Good article. Interesting results, especially with the .223. Not what I would have assumed prior to the testing results. With handguns, the old adage of heavy and slow wins the day still holds true.

  8. Over 20 years with various firearms and qualified as an expert nearly every time I certified. Still, the training concentrated on knowing what was beyond the target, or what could approach the target from either side. Imagine a child awaking in the middle of the night, rubbing his eyes as he heads for his parents room for reassurance. Better to not be so quick to shoot until you have a definite target and you know the area is clear.

    Many years ago a hunting magazine explained the difference between different calibers. It went something like this…. a .38 is good for plinking and pest control, a .357 magnum is good for small game and blowing holes in walls, and a .44 magnum is only good if your home is invaded by Kodiak bears.

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