Whether a sports car used for fun on the weekend, an SUV or minivan for hauling the kids, a pickup for pulling the camper, or a truck designed to haul 40,000 pounds or more of freight they are all vehicles. Even a Formula One race car or a motorcycle falls into the same class. Their purpose is secondary to their classification as such.
Guns are the same. All fall into the same class; and, that class is weapons. Purpose is secondary to their classification as such.
This is one of the best posts of the thread. A Glock is a weapon and a pistol, it's not a rifle. A standard AR-15 is a rifle and a weapon, it's not a pistol. A Glock and an AR have similar purposes, but are built for different situations.