Because firearm designs are so diverse, the exact definition of ‘handgun’ is tricky. Most folks understand handguns to include pistols and revolvers, but there are some other factors that come to mind. According to the US Federal Law, a handgun is defined as…
“… any firearm including a pistol or revolver designed to be fired by the use of a single hand. The term also includes any combination of parts from which a handgun can be assembled.” [18 U.S.C., § 921(A)(29)]
Unfortunately, this definition hinges entirely on the ‘intent’ of a design and not any objective specification. Barring injury or extenuating circumstances, no one shoots their pistols one-handed anymore. Does that mean today’s handguns aren’t ‘handguns’ anymore?
It also includes ‘any combination of parts’, which opens the door to abusive misinterpretation through constructive intent. With this definition, you could own a ‘pistol’ for keeping some spare piping and nails around the house.
The US Federal Government also has a definition for ‘pistol’:
“Pistol. A weapon originally designed, made, and intended to fire a projectile (bullet) from one or more barrels when held in one hand, and having (a) a chamber(s) as an integral part(s) of, or permanently aligned with, the bore(s); and (b) a short stock designed to be gripped by one hand and at an angle to and extending below the line of the bore(s).” [27 CFR § 478.11]
Sadly, this definition is just as confounding. They do specify some design features, but they are features found on many rifles too. Once again, we must refer to vague ‘intent’ for one-handed shooting.
In the end, there’s no perfect universal definition of ‘handgun’. Every state and locality will have its own variation, and no matter how we try to categorize the specifics of a handgun, there will always be some firearm that calls the definition into question.
For example: Do AR15 pistols count as handguns? In federal law, yes. In many states, yes, but not in all of them. That’s why it’s always important to do extensive research—because the lack of specificity on things like ‘handgun’ can make it challenging for gun-owners to know their position in the law.
Outside law, there’s little need for a perfect definition. If you’re discussing handguns, don’t get too tripped up on exact terminology. Focus on the context and don’t succumb to the mire of perfect verbiage.