Are Frangible Rounds Worth the Expense?

Dear Fellow Survivalist;

Amongst the various ammunition options there are for us to choose from are frangible rounds. Perhaps that’s a term you haven’t heard; but it’s actually been around for quite some time. Frangible rounds are specialty rounds, developed specifically for self-defense, indoors. The idea behind them is that they are designed in such a way that they supposedly won’t go through a wall, reducing the risk of hitting someone in a room behind your intended target.

I can hear someone out there, right now, saying, “If you hit the target, then your round won’t hit someone behind them.” Yes, that’s true. But it’s also true that it’s much harder to hit your target in an active shooting incident, than it is on the shooting range. Not only isn’t the target on the range shooting back, but it generally isn’t moving either. Then, of course, there’s the issue of adrenalin coursing through your system, messing up your small motor skills, like trigger control.

As for me, I’ll take every advantage I can get, even those that assume I’m going to make a major mistake, like missing my target. I can’t forget the case a few years back when a police officer had a shootout with a man high on drugs. By the time the suspect went down, the police officer had gotten 17 bullets into him. But he had fired 48 shots to do that… not exactly great odds.

An interior wall is nothing more than two layers of drywall, held in place by 2”x 4’s. not even the 2”x 4”s will stop a 9mm round, let alone the two layers of drywall. Considering that you can poke through those with a screwdriver, they really don’t make good ballistic protection.

Frangible rounds deal with this by breaking up on impact. They look similar to standard hollow-points, but rather than mushrooming when they strike, they break apart, allowing each fragment to create its own cavity and damage as it passes through the body. Since the individual pieces are smaller and lighter, they have less momentum, so are less likely to come out the other side. Should they hit a wall, rather than a body, they will also break up, with the idea being that the lower momentum will keep them from going through the second layer of drywall.

This may sound like the round is less-effective. After all, if it doesn’t penetrate as far, then it doesn’t do as much damage, right? But penetration isn’t the only measure of a bullet’s effectiveness. The famous .45ACP, fired from a 1911, doesn’t penetrate worth a damn. It was never intended to. Rather it was designed to transfer its energy to the target, giving up penetration for energy transfer. And there’s no question about the effectiveness of the .45ACP.

Let’s stop and think about this for a moment. We know the .45 is effective because of a combination of the bullet’s weight, the geometry and the muzzle velocity. Part of what makes it so effective is that it doesn’t penetrate well. Therefore, little energy is wasted tearing up tissue and almost all of it is transferred from the bullet, into the body that it strikes. High energy transfer leads to high knockdown power.

9mm hollow points are essentially designed to accomplish the same thing as a .45ACP, which is a little bit nuts, if you think about it. The 9mm Parabellum round was designed for penetration, so that it would reach deep into the body cavity, damaging critical organs and creating internal bleeding. A hollow point 9mm expands on contact, slowing the penetration and increasing energy transfer. It’s the same amount of energy, but rather than cutting through tissue, it is transferred to that tissue.

Ok, so what about frangible rounds. While they look much like normal hollow points, they are designed to self-destruct upon impact, with the part which would normally mushroom breaking apart into sections like flower petals and penetrating into the body on their own, creating additional damage trails. None of the mass of the bullet is lost, but some energy is consumed by the bullet breaking apart. However, where the majority of the energy is expended is by the pieces of bullet fragment traveling through the flesh. Since they are smaller, containing less mass, they have less momentum, so lose their energy faster. That’s good, because it gives us better energy transfer.

Overall, these rounds are less effective at penetration than their non-frangible cousins; while being better at energy transfer. That ability is what keeps them from going through the wall, should you miss and hit the wall instead. It also means that they should be fairly good in knockdown power. Since that’s really what we’re after, rather than intentionally trying to kill our assailants, that’s a good thing.

So, frangible rounds may be something you want to consider, especially if you’re likely to be in a defensive position indoors, where your bullets could travel through a wall and hit a family member. They’re just one more way of being prepared for the unexpected; just like keeping your powder dry and your survival gear close at hand.

Dr. Rich


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