There’s a lot of talk about assault rifles, but what are they really, and why is everyone so concerned about the AR-15?  To answer these questions, we’ll have to separate the hype from the data and get past the difference between appearances and reality.

Before we begin, I must state unequivocally that every loss of life is a tragedy.  No one wants to lose a loved one due to a firearm or any other means.  We forego the idea that we can prevent every tragedy, and instead look at ways that we can use our resources for the best possible outcome.

Weapons of Mass Destruction

The concern is that these assault rifles are weapons of mass destruction.  Their sole purpose is to kill as many people as possible, and therefore they shouldn’t be in the hands of civilians.  However, the story isn’t that simple.  First, let’s look at the data.  The FBI says that firearms make up 74% of murders.

Figure 1: 2019 Murder by Type, Source: US FBI UCR

Clearly, firearms are a big component of murder, but which types of firearms?  Figure 2 shows that it’s mostly handguns.

Figure 2: Murder by Firearm Type, Source: US FBI UCR

The unknown category – the ones where the weapon was unknown – is skewing the real picture.  If we assume that the unknown data is similar to the known data, we get Figure 3.  (Admittedly, this is an assumption, but it’s reasonable and doesn’t change the meaning of the analysis.)

Figure 3: Murder by Firearm Type when known, Source: US FBI UCR

What we see is that handguns account for 92% of the murders.  With rifles – the category under which assault rifles falls – represents 5% of the overall fatalities.  What most people would consider an assault rifle is a small subset of this.  Even if we ban all assault rifles, it will not make any substantial impact on fatalities.

Military Applications

The argument is that these weapons were designed for military application and therefore the public doesn’t need them.  There is a key difference between military weapons and the civilian versions.  The military versions allow for select fire.  Military weapons can fire in semi-automatic mode (one pull of the trigger fires one bullet), burst fire mode (one pull of the trigger fires three bullets), or automatic mode (one pull of the trigger fires bullets until the ammunition is exhausted or the trigger is released).

Though there are provisions for civilians owning fully automatic weapons, they’re rarely pursued because they’re time consuming and costly.  When we’re talking about the AR-15, however, we’re not talking about automatic weapons.  We’re talking about a weapon that is not fundamentally different than many of the hunting guns used by hunters today that accept a limited number of rounds in magazines and fire them with each pull of the trigger.

Often, the AR-15 platform is compared to the M16 military weapon.  There’s good reason for this: the M16 was based off the AR-15 and added select fire.  It also included a slightly more energetic cartridge – NATO 5.56x45mm instead of the .223 cartridge the AR-15 uses.  So, while visually similar, the M16 is capable of firing higher energy rounds in a fully automatic mode.

Appearances Can Be Deceiving

Ground effect lighting on a car doesn’t make it hover.  After the movie Back to the Future, it was popular for a while to put lights under people’s cars, not unlike the car in the movie or any of the other upgrades that people made to their cars like spinner hubcaps.  The visual appearance of a car with ground effect lighting may (or may not) have been cool, but it didn’t make the cars hover.  Appearances can be deceiving.

In the case of the AR-15, it looks like a military-style rifle – ironically, because the most popular military weapon was based on the platform.  However, the functionality is different – even if the looks are similar.

Modern Sporting Rifles

The National Sport Shooting Federation started using the term “modern sporting rifle” for the AR-15 platform in 2009.  Strangely, this signals a reduction in energy and the capacity to inflict injury than the weapons of the past.  As I explained in my post, Bullet Basics, the energy in a .223 cartridge, which the AR-15 uses, is substantially less than common hunting rifles.

Perhaps the AR-15 platform is a modern sporting rifle for the same reasons that it was selected by the military for newer weapons.  Lighter weapons are better – even if they are less deadly.