This post discusses some of the highlights of New York's gun laws.
Posses a loaded handgun, loaded sawed off shotgun, or loaded sawed off rifle? "C" armed violent felony. Punishable by a minimum of 3 and a half years and a maximum of 15 years.
Possess that same loaded gun in your home or at your work? An "A" misdemeanor, punishable by up to one year in jail. If the defendant already has a prior conviction, then possessing it at home or work doesn't matter. It becomes a "C" armed violent felony no matter where it is.
Possess an unloaded handgun, unloaded sawed off shotgun, or unloaded sawed off rifle? An "A" misdemeanor, punishable by up to one year in jail.
If that unloaded gun's serial number is defaced? A "D" felony, punishable from probation up to 7 years in prison. The law also says that if it's in your possession, it's presumed you knew it was defaced.
What about a person who has a permit, but violates the provisions of that permit? Examples of this are persons who carry a handgun on their person, but only have a permit that allows target practice. Or a person in Albany County who has a full, valid permit to carry, but carries the gun into New York City without special dispensation from the commissioner of police. That's an "A" misdemeanor, punishable by up to one year in jail.
What about out of state permits? New York doesn't recognize them. So, if you carry a gun in NY and you have an out of state permit, you'll be treated like you had no permit at all. That means a "C" felony, punishable by 3 and a half to 15 years. This was one of the reasons Plaxico Burress got in trouble.