Predictably, yet another mass shooting has led to yet another impassioned debate about the AR-15. And predictably, this debate will result in no useful outcome, because it is not the discussion we should be having. Instead of debating the AR-15, we should be talking about ammo and politics.
As many gun owners explain in every round of this debate, the AR-15 is just a semiautomatic rifle with some military-style cosmetics. Almost none of the features that gun control advocates get agitated about affect the lethality of the weapon, and they rarely talk about the things that do: muzzle energy, supersonic velocity, and muzzle power. We should be regulating these factors, not how the gun looks.
Muzzle energy is a function of the bullet’s mass and velocity. Velocity depends on how much propellant is in the cartridge, and the velocity is a lot more important than mass. Bullets don’t kill by imparting energy, they kill by causing bleeding, and a higher energy bullet can shred more flesh. The energy of a round is a much larger component of lethality than the way a gun looks.
Beyond the energy, whether a bullet is supersonic is also important. Supersonic bullets produce shock waves on impact, causing larger wound cavities. Subsonic bullets can tumble to produce more damage, but they don’t rip flesh far beyond the bullets path like supersonic bullets do.
Here are examples of supersonic wound cavities.
Muzzle power is my term for the rate of muzzle energy, so it’s how frequently bullets leave the muzzle and hit someone, a combination of firing rate and hit rate. For constant muzzle energy, a weapon that fires faster or hits more frequently will be more lethal.
That’s the physics of firearms lethality. What about the politics? We have two very committed factions, so there will have to be some compromises. Regulators must understand why people like firearms and how they use them so they can craft changes that control lethality while maintaining the non-lethal factors that gun owner like. We can reduce lethality while maintaining the utility of firearms for sport and defense.
For instance, the velocity of AR-15 rounds could be regulated, reducing the lethality for some shooters, and the maximum rate of fire of semiautomatic rifles could be reduced as well. Both of these factors could be tied to training.
For instance, maybe we could have several levels of training for firearms owners. At the lowest level, you could buy and own a large quantity of slow rounds but no fast rounds. With more experience, you could purchase larger quantities of higher energy rounds.
Mandating more training, and requiring experienced shooters to vouch for less experienced shooters, making it easier to identify crazies, but also making the most experienced shooters more respected senior members of their community.
New shooters could get light training and shoot as much as they want at a range, but only own less lethal rounds, smaller magazines, and weapons governed to shoot at a slower rate. Owning rounds useful for home defense and hunting would require more training and talking to more people who can tell if you are crazy.
Preventing mass shootings has absolutely nothing to do with how scary the gun looks, and the Second Amendment ensures we can’t ban firearms. But regulations can reduce lethality and make it easier to identify people who should not own guns. Let’s have those conversations instead.