One bone makes 5 bolts, I've never ran out of hunter's bolts with running bones into ammo with craftdwarves ( Just remember to unforbid any that's left around outside to save a bit ). I usually just make totems with skulls to sell to caravans, they're decently valuable for relative lack of effort!
They wont run out of ammo, but every 5 shots they got to run back for more, instead of the 25.
When I check my dwarves quivers they usually have 4 or 5 stacks of five bone bolts, I think the military setting for ammo has to do with it I usually increase it from the default 100 to 250 or something...
With bones there are a few bugs, for instance decorations and artifacts taking a whole stack of bones when they really need 1 bone, because of this I like to use the basic value bones to make bolts until only 1 bone is left in the stack, then I forbid the last bone to decorate some crap item left by caravan or sieges that I want to resell, for higher value bones I do the same but instead of making bolts I make crafts, and I reserve these single bones for a mood artifact.
Also if you want, you can wait until you have a legendary bone crafter to make the totems and place the masterwork totems somewhere in your fort as trophies of the fallen beasts that attacked your fort or something...
It's a nice strategy to "direct" your moody to use the highest value materials you have in your fort, recently one of my dwarves claimed a mason workshop and required 2 stones, I forbid every stone but gold nuggets (it was the highest value stone I had) and I got a native gold quern worth 103.000€, I guess my miller is ecstatic when he makes flour or dyes