This is a small toy pistol, appears on most platforms as water guns. In 2016, Apple redesigned this emoji as a pollution-free toy water gun in IOS10, and then the other major platforms also made the same changes. It can refer to the toy gun itself or the shooting sport.
🚫 We strongly advise you against using this emoji recklessly in social networking. This Emoji may look offensive and violent to someone, and that's why Apple Inc redesigned it. Emoji allows everyone to socialize more friendly, which is also the original intention of this platform.