Under 26 USCA § 861 (a), firearms is defined as “"a shot gun or rifle having a barrel of less than eighteen inches in length, or any other weapon, except a pistol or revolver, from which a shot is discharged by an explosive if such weapon is capable of being concealed on the person, or a machine gun, and includes a muffler or silencer for any firearm whether or not such firearm is included within the foregoing definition." United States v. Adams, 11 F. Supp. 216, 217 (S.D. Fla. 1935)

Law involving firearms governs the registration of any weapon which will or is designed to or may readily be converted to expel a projectile by the action of an explosive; the frame or receiver of any such weapon; any firearm muffler or firearm silencer; or any destructive device. Title 26, U.S.C., Sec. 5861(d), makes it a Federal crime or offense for anyone to possess certain kinds of firearms which are not registered to him in the National Firearms Registration and Transfer Record. Laws govern who may own firearms, such as prohibiting felons to carry guns, childrens' access to firearms, recordkeeping, transport, and licensing of those dealing in firearms. Federal law makes it unlawful for any person except a licensed dealer to engage in the business of dealing in firearms. Some states have also adopted dealer regulations.

Federal law does not regulate the carrying of concealed weapons. It does, however, provide that persons who have been issued state permits to purchase or possess firearms are exempt from background checks if those permits were issued: 1) within the previous five years in the state in which the transfer is to take place; and 2) after an authorized government official verified that possession of a firearm would not be unlawful. States may adopt laws requiring background checks under such circumstances, however. Most states allow the carrying of concealed weapons by persons who obtain a permit.

The Brady Handgun Violence Prevention Act of 1993 amended the Gun Control Act to require federally licensed firearms dealers - but not private sellers - to perform background checks on prospective handgun purchasers to ensure that the firearm transfer would not violate federal or state law. Prior to the adoption of the Brady Act, gun sales were governed by the “honor system,” i.e., a dealer was permitted to rely upon the representations of a purchaser regarding his or her eligibility to own firearms.

The following is an example of a state law dealing with possession of firearms by felons:

"Ownership or possession prohibited, when; penalty. (a) No person who is a fugitive from justice shall own, possess, or control any firearm or ammunition therefor. (b) No person who is under indictment for, or has waived indictment for, or has been bound over to the circuit court for, or has been convicted in this State or elsewhere of having committed a felony, or any crime of violence, or an illegal sale of any drug shall own, possess, or control any firearm or ammunition therefor.

(c) No person who:

Is or has been under treatment or counseling for addiction to, abuse of, or dependence upon any dangerous, harmful, or detrimental drug, intoxicating compound as defined in section 712-1240, or intoxicating liquor; Has been acquitted of a crime on the grounds of mental disease, disorder, or defect pursuant to section 704-411; or Is or has been diagnosed as having a significant behavioral, emotional, or mental disorders as defined by the most current diagnostic manual of the American Psychiatric Association or for treatment for organic brain syndromes;shall own, possess, or control any firearm or ammunition therefor, unless the person has been medically documented to be no longer adversely affected by the addiction, abuse, dependence, mental disease, disorder, or defect.

(d) No person who is less than twenty-five years old and has been adjudicated by the family court to have committed a felony, two or more crimes of violence, or an illegal sale of any drug shall own, possess or control any firearm or ammunition therefor.

(e) No minor who: