Actually, agility increases your crit chance and your attack power, which is how it increases your ranged damage.  I was worried when I hit outland and I was getting +crit and +attack power everything, and was losing agility on gear, but +crit combined with +attack power is the same as agility, and often times in Outland, you get more crit and attack power separate than agility would provide were it the stat on your weapon.  The only thing that you lose by not having agility on a weapon as opposed to +crit and +AP is the small armor bonus that you get from agility, but most of the time the armor upgrades are worth losing 4 armor or something piddly like that.

Hope I didn't lose anyone, sure made sense when I was thinking it : )

for hunters, agi increases crit rating by some, and 1 AP for each point in agi... so, if yo go purely for ap, you don't crit much, but go for agi, and you get several crits per fight and a decent white dmg.

if you've come this far as to get this gun, you really should know this by now ^^