Bullet Behavior, Part I


I am a firm believer in being a student.

I remember my grandpa telling me when I was 9 years old that:

“If you are not learning something every day son, you are doing yourself a grave injustice and are well on your way to becoming a FOOL!” 

The CO, in order to function at maximum capacity, needs to be a student of many things also in order to survive. One of the main ones being Firearms and Ballistics. But going beyond just the facts you might find in the ballistics tables of the Shooters Bible are the sorted tales of the unpredictable behavior of bullets fired in training and combat.

We all have heard stories about richochets, skips, bounces and amazing bullet penetration through various objects and mediums. But I think for the CO to really become a TRUE Rifleman, Shootist or if you prefer the overly verbose nom de guerre; “Practitioner of the Firearm Arts”, they have to be able, with great certainty, to separate URBAN MYTH/ “GUN SHOP” BULLSHIT from REALITY.


Bullet Penetration

This is a subject that for the CO, can serve him equally well either offensively or defensively. Knowing what (to a certain degree) materials or medium a bullet can or cannot penetrate can help both keep the CO alive (through cover) and kill their enemies easier (shooting through concealment). An eon ago, when I started collecting Curio and Relic Firearms, a friend of mine directed me to a fellow Texans web site that he thought I might enjoy; The Box O’ Truth. Upon visiting it however, I soon found out that C&R Weapons was just one of the many topics covered; the main emphasis was ammo penetration testing..very cool discovery!

Since the Box’O Truth is what I consider one of the best REFERENCE websites on the web for ammo penetration, I will leave it to you to peruse their extensive files, and draw your own conclusions about bullet penetration myth and reality. But, I would urge you to donate a few dollars in the process; Don and his Crew at the Box spend a lot of their own time and own money to build the extensive reference site that you and me enjoy every day, let’s help em’ out!

I did want to go a little deeper on a couple of materials I think relevant to the CO regarding penetration before moving on from this subject, namely, materials the CO will typically be taking cover behind and/or shooting through during a skirmish;  Sheetrock and Vehicle Doors & Glass.

I have used the B.O.T extensive library for my findings, but also included some personal experiences to help the CO draw their own conclusions.


Since sheetrock is used in just about every type of building construction, and most of us have it in our houses, it is a practical material to start with. To make this evaluation easy for you, it SUCKS as far as stopping bullets! B.O.T. tested both 5/8″ and 1/2″ Sheetrock. To answer a common question I hear a lot in training: “Isn’t it true that most all walls in a standard home are insulated? Wouldn’t that make a difference in penetration?” Answer: Only EXTERIOR walls are insulated typically, but, NO, as a general rule, it did not make a difference in the test. The B.O.T boys proved this fact also…see HERE.

The guys also tested Shotgun loads, and the results were similar. Boil it all down and you come up with the same conclusion:  Sheetrock SUCKS for Cover!

There is a duality here for the CO. Knowing the above information, The CO definitely needs to train HOW to shoot an intruder (inside a structure) and subtract and/or takeaway the threat of over-penetration. Besides switching to frangible ammo (which we will discuss in a future article), some simple baseline tactics involve knowing your background and changing the shooter’s position prior to the shot. Secondly, armed with the same information along with an in-depth study of how the CO’s particular firearms and defense ammo behave through sheetrock, the CO can now take a shot THROUGH sheetrock with confidence against an intruder, if need be.

A quick note about shooting through sheetrock. Personal Experience has taught me several things on this subject:

  1.  Remember your Background! The Number 1 Rule in Firearms Safety, Period!! What is behind the wall you are shooting through (beside the bad guy?) What is behind the room the bad guy is in? If you are working with a team or family members are still present in the house, where are they?

  2.  Shoot more than one round..in fact, I would say shoot at least five to six. Bear in mind you are shooting blind, so this is essentially “Recon by Fire”; after you have shot, gauge how effective the rounds were; if you hear movement or if you take return fire, obviously, KEEP SHOOTING! (Typically, a large thud or groan/scream is a good sign you hit your target).

  3.  Aim where you want to hit. It has been my experience that sheetrock does not change the trajectory of a bullet that much if any, hollow points included (As the B.O.T confirms).

Of course, ALL of this advice, is heavily Situation Dependent. Ask yourself: Is it Safe? (Notice how I keep coming back to this!?) Do you really want to give away your position by shooting blindly through a wall? Can I wait for a cleaner shot?


Vehicle Doors & Glass

Besides our homes and work, our vehicles are where most American spend a majority of their time. Either commuting too and from work, that weekly trip to the grocery store or taking kid’s to soccer practice, vehicles are a large part of our lives. So it makes total sense for the CO to spend a LARGE part of their training time learning to FIGHT efficiently IN, FROM and AROUND Vehicles.

In accordance with vehicle combat training, is the essential knowledge of what MOST bullets do when fired through vehicle doors and glass. I picked these two categories, because experience has shown that these two area’s take the most action in a typical vehicle skirmish.

Thankfully, B.O.T.’s illustrious “Buick of Truth” helps us answer these questions without having to go out in our beloved rides and get shot at to find out! A quick word about the Buick of Truth: This particular model contains power windows and locks, meaning that there is much more “equipment” (ie motors and gears) in the door panels than a non-power locks/windows model, giving the bullet more things to hit and/or deflect off of. Something to think about while you are drawing your conclusions.

OK, so the first “experiment” was pistol rounds, as you can see, they chopped through the Buick like butter, some of them even penetrating all the way through the passenger door! This should tell you that in no uncertain terms what the rifle rounds are going to do!! So, in essence guys, vehicle doors SUCK for Cover, don’t use them nor depend on them!

Moving on to Vehicle (Laminate Safety) Glass. A quick word about factory vehicle glass: Most factory auto glass is safety-laminate, which means it is shatter proof and designed not to shatter into a thousand shards upon impact. It is extremely tough and has dramatic effects upon bullets, as we will see.

As far as B.O.T’s files, the only examples they have are for Pistol rounds fired from the outside and the inside of a STATIONARY Buick. The results show how much standard Ball ammo fragments through the glass, also note how much the trajectory is retarded from the original point of aim. The conclusions on the last page are spot on.

To boil it all down; Shooting at a person inside a stationary, not to include a moving vehicle is a precarious affair at best; not only are the odds that you will actually hit your intended target at the point of aim very low, but the odds are greatly increased that you will also hit other people in the car. This is what the Military and HRT call “LOW PERCENTAGE SHOTS” or in plain speak, Shots that should not be taken unless absolutely necessary!


On that note, a short story about fighting from vehicles. I guess you could call it my “Murphy’s Law Story”  because in essence, it really applies to combat in general. It has been my experience that in having been both shot at inside a vehicle and having shot at moving and static vehicle’s (in pursuits and ambushes) that it is really a “crap shoot” in how things turn out, simply because in real-world combat, things move very fast! People do not stand still when shot at..they move quickly, typically in the opposite direction you are! In a dynamic vehicle situation, I can liken it to skeet shooting.. for those of you who have shot skeet, you know the #1 rule:, You don’t shoot where the target IS, you shoot where the target is going to BE. Add all of this up, combining all the variables listed in shooting at just STATIONARY vehicles, and you have a very dynamic, unpredictable soup!

I mean just consider for a moment trying to hit a 60mph moving target by itself with just a pistol and no other variables…NOW add to this putting a barrier in front of that target (windshield) that depending on the angle, can deflect your shot to such a degree as to cause a total miss, PLUS the glass material can fragment your bullet to such a degree as to reduce it’s killing power to NILL. To boil it all down: Gunplay in vehicles is an extremely dangerous, high risk, LOW PERCENTAGE SHOT activity that SHOULD NOT be attempted unless absolutely necessary.

But for the CO to be prepared to fight in a dynamic, real world environment, he MUST train for that day when it becomes necessary! Stay tuned for Part 2 where we will cover training to take that shot, ricochets and much, much more!

Stay Dangerous!

5 thoughts on “Bullet Behavior, Part I

  1. Pingback: Civilian Operator 101: Stopping a “Jihad-Mobile” | Hammerhead Combat Systems

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