Blame Hollywood.  Blame the evening news.  Blame your Uncle Jim.  There is a lot of incorrect information out there on firearms and ammunition. 

For whatever reason, bullet design and performance seems to have the largest amount of myths and half-truths circling around it.  Some of these false beliefs have led to bad movie scenes and even worse, bad laws.

When a handgun is loaded for self defense, most instructors advise to use quality hollow point ammunition.  But why?

The Hollow Point Bullet

The idea of a hollow point it to cause the bullet to expand when striking the target.

A hollow point is not a “Dum-Dum” bullet.  The Dum-Dum bullet was developed in the Dum-Dum arsenal in India in 1897.  It was a rifle bullet with an exposed lead tip.  The bullets were never fully developed and discontinued in 1899.  Yet, to hear the media tell it, Dum-Dum bullets are the preferred ammo choice by gang bangers everywhere.

Why a Hollow Point

Generally speaking, to stop a violent attacker with a handgun, the bullets need to either disable the central nervous system (brain, spine) or cause massive blood loss which fuels the brain and muscles.  So called “head shots” are difficult targets, so most instructors train students to aim at the “center of mass”: the upper torso region housing the heart and lungs.

Without trying to sound crude, the bigger the holes you make in an attacker, the quicker he will bleed out and no longer threaten you or your loved ones.  This is why many people prefer a .45 ACP to a 9mm.  But, hollow points can make smaller cartridges more effective.

When a hollow point strikes flesh, it is designed to expand, opening up like a mushroom.  As the bullet expands, it can cause more tissue damage, which in turn more quickly renders the attacker unable to assault you.

While precise measurements vary, under ideal conditions, a 9mm bullet can expand to nearly double its size (from .355” to nearly .7” in diameter.)  Likewise, a .45 ACP bullet can expand to almost an inch in diameter.

Speed Kills

Just because a bullet is a hollow point is no guarantee that it will expand.  In fact, a great many hollow points fail to expand when used in self defense shootings.  Why is this?

There are several factors that affect hollow point expansion, but I’ve found the two most critical are the bullet design and bullet speed.

Current premium bullet designs take into account the latest information from the labs and the streets to ensure the bullets expand under a wide range of conditions.

No matter how good bullet designs are, though, all of them need a minimum amount of velocity to ensure proper expansion.  This is especially important when a hollow point is plugged by the clothing worn by an attacker.

Generally, I have found that the narrower the bullet face, the more velocity needed to cause reliable expansion.  In other words, a wide mouth .45 bullet is more likely to expand at lower velocities than a narrow 9mm.  Narrow, low-velocity cartridges, like the .25 ACP and .32 ACP, rarely expand.

Some bullet designs are specifically designed for lower velocities experienced in short barrel firearms.  For example, the Speer Gold Dot 135 gr load designed specifically for snub nosed revolvers.

Designs like the Critical Defense ammo help prevent the hollow point cavity from plugging by having a flexible polymer in the cavity.  When the polymer is compressed, the force pushes against the interior walls of the cavity, enhancing expansion.

Penetration is Good, Over-Penetration is Bad

Non-expanding bullets tend to go right through the body, exiting the bad guy and continuing in flight.  Expanding bullets tend to stay in the body of the attacker.

Notice I say “tend to.”  There are no absolutes, and I can show you cases where hollow points expanded, yet still exited the torso, and cases where a non-expanding bullet stayed in the attacker.

Bullets that over-penetrate, exiting the attacker, present several problems:

– they fail to achieve maximum energy and momentum transfer, and

– they present a danger to others in the area who may be struck by the still flying bullets.

No matter what theory of stopping power you subscribe to, bullets that stay in the body tend to create larger temporary and permanent crush cavities because the bullets transfer more/all energy and momentum.  The more “work” the bullet does on the attacker’s body, the quicker the attacker will cease his violent assault.

The number of bystanders struck by over-penetrating bullets may be small.  But, if your bullet kills a bystander, are you prepared to deal with the psychological, moral and legal consequences of that?

Hollow Points – Don’t Believe the Hype

Hollow point bullets are an integral piece of safety equipment when we talk about stopping a violent attacker.  They are likely to stop a violent attack quicker than non-expanding bullets.
For some reason, a lot of myths surround hollow point bullets.  Don’t buy into myths and wild guesses. 

To stop an attacker with a handgun, you need to get multiple shots on target quickly.  Quality hollow points will simply make those shots more effective, and that is a good thing.

Editor’s Note:
Thanks to Richard Johnson for this article. I encourage you to visit his website and explore all the guns, ammo and gear. ~Mike P.

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