Originally Posted by StanSimmons

One can use other non-gun "guns" as well. I've read of people using movie prop guns, airsoft guns, bb guns, and starter pistols. To meet the definition of the FAR, a gun must propel a projectile by means of an explosive charge. A flare gun meets this, but the other examples do not... but they look enough like a gun that it is generally a good idea to declare them as guns if you pack them in a suitcase.

Those other examples aren't guns, and might be ok on a plane, (I haven't bothered to check) but don't try to take them thru a checkpoint, you would only confuse and annoy the TSA employees.