I remember having this conversation/debate with a guy that work in Walmart's hunting and fishing section. He said many jurisdictions classify airguns as "firearms", even though there isn't any "fire" involved in the operation. Basically, it's a murky set of standards that makes it so anything that propells a pellet, slug, bb, etc. over a certain feet per second, a firearm. As such, making all rules governing actual handguns effective for airguns (discharge in city limits, used in the comission of a crime, brandishing, blah, blah, blah)