I don't hunt myself, but wooden bolts are basically training ammo, and thus not very good for killing stuff, so even if all of the 25 wooden bolts find their mark, it doesn't mean the mark will go down, although it can happen. I expect bone ammo to be a little bit better, probably to a usable level.
If your hunter drops the catch you might get someone else to collect it if you change the refuse collection settings ('o'-'r'-'o' I think) to get the dorfs to collect bodies (and dump marked items) from the outside. Refuse collection requires you to have a refuse stockpile to which they can haul the carcass (and the butcher then would collect it there to cut it up; dorfs aren't up to current sanitary standards). If you don't have a refuse stockpile to receive the carcass you can use a dump area and dump designate the body instead. Someone said the butcher shop will collect bodies from within 50 tiles or so. Note, however, that you need to un'f'orbid the body when it has been dumped, or the butcher won't touch it (if you've got a refuse stockpile a dorf will probably haul it there before the butcher can get to it as soon as you unforbid it).
It seems refuse hauling dorfs are so cool about their task that the body they're hauling isn't subjected to rot while carried, even if it takes a month to haul that Rutherer body out of the cavern it fell in.