Shoddy arrows can be made by one engineer and a survivalist working together near a forest with suitable rocks. They can create 15 arrows with a success on both survival and engineering, and 15 more for a each double raise (one raise in survival and one raise in engineering). These arrows are shoddy, and suffer from a -1 to hit, and cannot be recovered.
Proper arrows can be recovered with a roll of 4+ on a d6 after combat, assuming the arrows are in a position in which they can be recovered. On a roll of 2 or 3 the arrow is recovered, but is broken, and needs to be fixed (with a succesfull engineering check for up to 8 arrows an hour). On a 1 the arrow is FUBAR.