Yes, it does depend on the weapon.
Convergence will matter for nose mounted weapons. When you specify convergence in AH, it will adjust the vertical angle of the weapon as well as the horizontal. So, regardless of where you set your convergence, make it the range you plan to do your killing at.

FYI, I fly the Jug, and with 8x.50 wing guns, convergence is very important. I use a convergence of 300 for all guns and it works pretty well. The best idea is to try different convergences for your plane and choose the one that works best for you.
------------------
Sean "Lephturn" Conrad - Aces High Chief Trainer
A proud member of the mighty Flying Pigs
http://www.flyingpigs.comCheck out
Lephturn's Aerodrome for AH articles and training info!