... Ammo alone for hunting cant be done,...
You do know there are Hunters and SQUADS in the ammo screen right Meph?
even if it's only for hunting (combat/training) you can just tell hunters to use "hunting ammo" for their combat needs (hunting)
little bit of micro managing but meh. I was thinking hunting arrows would be like Hollow Point bullets (or in this case broad head arrows, lots of cutting, lots of bleeding)
@Armor Idea
Chainmail I thought was more against slashing type attacks and some blunt (but then again I am thinking old medieval chainmail, and not the modern mail that divers mainly use that can stop all sorts of piercing (mainly shark teeth)) but really I don't think any chainmail would be effective against an arrow/bolt the shear force they are fired at, and small contact area usually punches through most things. Only way I could see armor working against an arrow would be if it was layered (Plate,chain,wood(oak/maple),leather) even then that's taking a gamble and would make you look really bulky and heavy due to the thickness of wood needed to hopefully stop an arrow.
Just my 2 cents
But all in all DF armor and ranged fighting works vastly different from RL. You could make a piece of armor strong against arrows, but then you just make an all around protect against all types of weapons armor.