From there :
http://wiki.project1999.org/index.php/Game_Mechanics
Weapon Proc Rates
*
http://everquest.allakhazam.com/wiki/eq:Proc (~Live, sounds right)
*
http://www.thesteelwarrior.org/forum...ad.php?t=13613
Proc rates are computed on a procs per minute basis. I believe this is the same number for the vast majority of weapons, but some weapons have a higher adjusted procs per minute rate, and some such (with big procs) are adjusted downwards. The game translates the weapons targeted procs per minute and applies it to your weapon. If you are swinging 100 times a minute with your main hand, and the targeted procs per minute is 5, then the game essentially makes this computation:
* 5 procs divided by 100 swings = chance to proc per swing
* 5 / 100 = 0.05 or 1 in twenty chance.
Now if your haste wears off, and you're only swinging 50 times per minute, the game actually will up your chance to proc per swing
* 5 / 50 = 0.10 or 1 in 10 chance to proc per swing
This is confusing to some people but it's definitely true.
So from what I read, the answer to your question is : Some weapons have a higher proc rate than some others for a same Dexterity value.