Check out section#3 in the Rhode Island bylaws of what their definition is of a firearm. As you can see, BB guns and Air rifles are considered Firearms in the state of Rhode Island.

TITLE 11
Criminal Offenses
CHAPTER 11-47
Weapons
SECTION 11-47-2


§ 11-47-2 Definitions. – When used in this chapter, the following words and phrases are construed as follows:

(1) "Antique firearm" is defined as that term is defined under the provisions of 18 U.S.C. § 921.

(2) "Crime of violence" means and includes any of the following crimes or an attempt to commit any of them: murder, manslaughter, rape, first or second degree sexual assault, first or second degree child molestation, kidnapping, first and second degree arson, mayhem, robbery, burglary, breaking and entering, any felony violation involving the illegal manufacture, sale, or delivery of a controlled substance, or possession with intent to manufacture, sell, or deliver a controlled substance classified in schedule I or schedule II of § 21-28-2.08, any violation of § 21-28-4.01.1 or 21-28-4.01.2 or conspiracy to commit any violation of these statutes, assault with a dangerous weapon, assault or battery involving grave bodily injury, and/or assault with intent to commit any offense punishable as a felony; upon any conviction of an offense punishable as a felony offense under § 12-29-5.

(3) "Firearm" includes any machine gun, pistol, rifle, air rifle, air pistol, "blank gun," "BB gun," or other instrument from which steel or metal projectiles are propelled, or which may readily be converted to expel a projectile, except recurve, compound, or longbows, and except instruments propelling projectiles which are designed or normally used for a primary purpose other than as a weapon. The frame or receiver of the weapon shall be construed as a firearm under the provisions of this section.