Yes. Under the Gun Control Act (GCA), shotguns and rifles, and ammunition for shotguns or rifles may be sold only to individuals 18 years of age or older. All firearms other than shotguns and rifles, and all ammunition other than ammunition for shotguns or rifles may be sold only to individuals 21 years of age or older. Licensees are bound by the minimum age requirements established by the GCA regardless of State or local law. However, if State law or local ordinances establish a higher minimum age for the purchase or disposition of firearms, the licensee must observe the higher age requirement.
[18 U.S.C. 922(b)(1) and (b)(2); 27 CFR 478.99(b)]