Alpha Wolf Wonderlus over at Tabula Rasa Vault has done us all an enormous favor by posting a disassembled item chart that shows what sort of components you're liable to get from a weapon with a given modification. It's still only a matter of probability whether you'll get a certain item, but it's good to know where to start looking if you've got a specific modification in mind.
This will come in handy if I ever make it to level 50 and make a crafting clone, which is just about the only time that crafting in Tabula Rasa is viable. Since crafting talent points are drawn from the same pool as combat abilities, most people don't bother trying crafting until after level 30, when it becomes possible to make a clone with all the crafting talents maxed out. Still, it's neat!