JACK™ HPA Conversion Kit - Blemished Poppet Valves with adjustable nozzle dwell and

with adjustable nozzle dwell and return speed

The original HK417/G28 stocks use a larger diameter buffer tube and therefore cannot be used on the CO2 inserts

If it's crooked

the system incorporates a very intelligent design and is unlike anything else on the market

JACK™ HPA Conversion Kit - Blemished Poppet Valves with adjustable nozzle dwell andWe have a limited number of blemished JACK V2s available at a substantial discount. During each production run there are always some parts which do not pass QC inspections. In some cases these parts are dimensionally out of tolerance and unusable so they are scrapped for recycling. In other cases the parts are completely functional but have minor defects in "Class A" surfaces. These blemished systems are factory new but built with one or more parts