With some time on my hands, I borrowed heavily from the LUG trek books and made some (draft) 24th Century FASA Star Trek ranged weapon (phasers and disruptors) stats conversions. I did it just for the fun of it.. sadly, my RPG days are long gone. However, every Fall season, I feel the urge to GM strongly, so this is my way of caving in to those feelings... by doing these stats.
For the Jem'Hadar weapon that fires several bursts per round, perhaps a -5 or -10 cumultative modifier might be in order after the first shot.
Needless to say, like RPGing in the 23rd Century, GMs, especially inexperienced GMs, have to be very careful when NPCs shoot at PCs with energy weapons. You don't want a stray shot from a nameless NPC to kill off a beloved character just by the roll of the dice. If they have to be shot at, give the PCs some leeway, with generous cover, dodge rolls and if hit, luck rolls, but don't make it too obvious.