Been long time since I posted, I have been doing a bit of shooting arrows from my 909's 45 calipers, Finally figured out the perfect nock to fit the 45 caliper, Without spending a lot, Here is what I used" A empty 9mm bullet casing a 0-ring and some super glue and a {8.9mm o/d 400 vane 22 inch carbon fiber arrows} I purchased from AliExpress, At { YEZ Archery 001 Store}, fit snug to the spent 9mm casing with the O-ring [sized to YOUR 45 caliper barrel, Any gun range has plenty of used casings. spent $11.65 for 12 -22inch 400 vane carbon mixed tubes, these work, maybe someone else would post if they have a better nock creation? Other than buying the arrows from venders at $99.00, Any ways good luck hope it works for you. too I think this post needs to be moved to Air archery gate,[ please.] Thanks, ModeratorYEZ Archery 001 StoreYEZ Archery 001 Store