I make my own (muzzle loading inside the barrel, not the "slip onto a barrel tube" type) air bolts for my .357 Challenger using the following:Arrows, $25 per dozen: Nocks, 9mm, $6.29 per 50, hot glued into the arrows above:If needed, grommets for the barrel end of the arrow to center them. So far I have not needed them. $14 for a 210 pack:I remove the nock from the arrow, then hot glue the rubber bumper into the hole left by the nock, applying the hot glue liberally. I also remove the vanes from the arrows. After the hot glue dries it is ready to fire.A word of caution in advance: I have a large 18" deep home built target made to stop crossbow bolts with field points at 350 fps with an 8-10 inch penetration and arrows from my collection of compound and recurve bows are also stopped by it handily. Arrows fired from my .357 Challenger pass through it completely barely slowing down and easily exceed 300 fpe of force. Don't shoot these at anything unless you have no doubts about whether or not it will stop the arrow.