Had an interesting experience, which is probably a symptom of one or more bugs, but I don't really think I have enough detail to write a good bug report for it.
One of my dwarfs made an artifact bow (not crossbow). One of my hunters decided to equip it. Call this Hunter 1. Hunter 1 then proceeded to fill her quiver with bolts. Result: no hunting. OK, fine -- assign her some other labors and let her carry the stuff around unused.
Hunter 2 grabbed a bronze crossbow, a quiver and some bolts, and hunted normally for a while.
At some point I got curious -- I wanted to see what would happen if I assigned arrows to the hunter pseudo-squad. When the elves came, I bought 2 stacks of 25 wooden arrows. I assigned 50 arrows to the hunters (not specifying material). Hunter 1 did not grab arrows -- she kept her quiver full of bolts.
Hunter 2, on the other hand, eventually ran out of bolts and then stocked his quiver full of arrows. While still wearing the crossbow. Result: no hunting.
I tried dumping the arrows in a garbage zone, but that didn't help (he just kept an empty quiver). I tried removing the arrows from the hunters via the military screen. That also didn't help. He was dead set on using those arrows, or nothing.
Finally I decided to destroy them utterly. I set up a bridge, a lever, a door. I smashed the arrows into nothingness. Result: Hunter 2 grabbed bolts and started hunting again. Hurrah!