Medi-Dart needle/valve assembly #5 (MDAKH5)

Details

Rebuilding the front of a Medi-Dart syringe one small part at a time is how people end up with a dart that holds pressure on the bench and leaks in the field. This assembly sidesteps that. It arrives as a matched needle and valve group built around the #5 needle, so the needle, seat and valve parts are known to work together rather than being assembled from whatever was left in the drawer. The #5 is at the rough end of the Medi-Dart ridge range. On these needles the number describes the ridge alone, and the rougher it is the better the needle holds while air pressure drives the plunger down the barrel. That is the grade most crossbow kits were originally supplied with, which makes this assembly the natural replacement for an outfit that has been running a few seasons. This version does not include a wingnut. If you need one, the wingnuts are sold on their own in 13 mm (1/2 in) for cows and bulls and 9.5 mm (3/8 in) for younger cattle up to yearlings, or you can order the assembly that comes with one already fitted. The needle and valve components are reusable parts with a service life rather than consumables; the o-ring is the item most worth keeping spares of. Check the assembly holds air before you go out, and leave the treatment decisions to your veterinarian and the label on whatever you are administering.