Deflect Arrows is a combat feat that allows to deflect projectiles once per round when I would normally be hit by the projectile. The only projectiles listed as non-deflectable are:
Unusually massive ranged weapons (such as boulders or ballista bolts) and ranged attacks generated by natural attacks or spell effects
A bullet shot from a firearm has very low mass (even though velocity is likely high). I don't know of any bullets generated by natural attacks, nor by spell effects.
So, did I get the rules right, can I really be that badass and deflect one bullet per round with one free hand?