Yup, nothing better than taking the word of advertising agents to determine what words actually mean...
A revolver is not a pistol and a pistol is not a revolver.
They are both handguns.
I will take the legal definition, the one prescribed by anyone that knows anything in the editor and writer world, and the common sense definitions.
Anyone that wants to use the others is welcome to have at it. They can enjoy attempting to bemuse those with a clue...
