Medi-Dart needle #3 (MDN3)

Details

Grade selection is where most of the guesswork sits with this system. Medi-Dart runs its needles from #2 to #6, and the only thing the number describes is the ridge: the higher you go, the rougher the ridge and the harder the needle holds while the pressurised barrel empties behind it. The #3 sits in the middle, a step up from the smooth #2 without going to the heavy grades. Like the rest of the IM line, the #3 discharges through the solid tip. The Sub-Q needles in the catalogue are the ones drilled with two holes in the side of the shaft, and they are a separate range rather than a variation on the same part. If the label you are working from calls for a different route, the needle changes with it, and that call belongs with your veterinarian. This is not a throw-away part. Medi-Dart rates a needle at about thirty injections used on the crossbow and about fifty on the extension pole syringe, and a few strokes with a file will restore a point that has gone dull. Retire it when the ridge stops holding or the shaft is no longer true. The #3 threads onto either the extension syringe or the crossbow dart through the small nut. Keep the o-ring and valve seat in good order at the same time, because a well-seated needle behind a tired seal will still bleed air and cost you the shot.