When i was a veterinary student some nighrts we had to stay at the surgery i.c.u. and just to not getting bored we had some blowgun contests, we  used thin pvc pipe about 8 mm diameter and 5 to 6 feet long as blowguns, darts were steel pins (those we use to drive bone surgery nails) about 4 to 6 inches lenght and 1,5mm section we just taped some coton with plaster tape. we had to use pliers to extract darts from wood target,
Later i've used easton aluminium arrow shafts with bamboo skews and some coton tied with sewing thread, not as powerful as the longer pvc tubes, but still stabbing skews into cardboard, soft wood and stucco walls.