Loading a Firearm: You need at least one hand free to load one-handed and two-handed firearms. In the case of two-handed firearms, you hold the weapon in one hand and load it with the other—you only need to hold it in two hands to aim and shoot the firearm. Loading siege firearms requires both hands, and one hand usually manipulates a large ramrod (which can be wielded as a club in combat). The Rapid Reload feat reduces the time required to load one-handed and two-handed firearms, but this feat does not reduce the time it takes to load siege firearms.
A character without this feat (Rapid Reload) needs a move action to reload a hand or light crossbow, a standard action to reload a one-handed firearm, or a full-round action to load a heavy crossbow or a two-handed firearm.