someone stopped by searching for “what is an illegal gun.”:
Well, a 1 gauge shotgun in a duck blind would qualify as an illegal gun, or a shoulder fired rifle in 20mm caliber without a special permit. But we don’t have many guns that are per se illegal.
Generally what is meant by “illegal gun” is a gun that would be legal for an ordinary citizen to own, and carry, but that is in the possession of someone who has lost his or her civil rights by reason of the commission of a felony.
So the proper phrase is not “illegal gun” but an “unlawful possessor.” More specifically, it almost always refers to a “felon in possession,” a person committing a crime by looking a second time at a gun.