About a decade ago, a gentleman (called "Geezer") made 0.50 cal. hunting darts using a #11 exacto blade hot glued into a long (think of the ones you get at Arby's) plastic straw. He used foam plastic circles punched out from a packing sheet (about 4 of them) as his plug (tailcone). He was from N.C., if I remember correctly, and said they were very effective for small game (squirrels, pigeons, etc.).