Atlas pistols have a secondary firing mode that allows them to use one of several types of tracking rounds that can be used to tag enemies. Once tagged, all normal rounds will track the tagged enemies for an amount of time that is dependent on what kind of tracking device was fired.
The AX-88 fires rockets instead of bullets. Each shot fired consumes 2 rounds of ammunition. If the weapon isn't tracking a target using its secondary fire mode, the rockets fly erratically, making it impossible to hit targets at a distance.
Rockets fired by the AX-88 deal splash damage and benefit from skills that grant effects based on splash damage, such as Moze'sFire in the Skag Den skill.