You can load crossbows with blinding speed and even fire them in melee with little fear of reprisal.
Benefit: The time required for you to reload any type of crossbow is reduced to a free action, regardless of the type of crossbow used. You can fire a crossbow as many times in a full attack action as you could attack if you were using a bow. Reloading a crossbow for the type of crossbow you chose when you took Rapid Reload no longer provokes attacks of opportunity.
Special: Starting at 6th level, a ranger with the archery combat style may select Crossbow Mastery as a combat style feat.
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.