SRD:Repeating Heavy Crossbow

Description
The repeating heavy crossbow holds 5 crossbow bolts. As long as it holds bolts, you can reload it by pulling the reloading lever (a free action). Loading a new case of 5 bolts is a full-round action that provokes attacks of opportunity.

You can fire a repeating crossbow with one hand or fire a repeating crossbow in each hand in the same manner as you would a normal heavy crossbow. However, you must fire the weapon with two hands in order to use the reloading lever, and you must use two hands to load a new case of bolts.