Technically none of this stuff really have names. Did you ever hear the rifle in any movie ever be referred to as an EE-3, or the ST blasters being called E-11's, or Han's blaster being called DL-44?
All of the names on the props in the movies are merely the work of someone coming up with something that sounds like whatever it is would be called.
Most people other than us really even notice the existence of Boba's sidearm in ESB so it is doubtful that there really is an "official name." I would say we should have a contest to see who can come up with the best sounding gun designation that hasn't already been used on something else, and we'll call that the official name.