newer version kit w/lathe-turned guide rod/spring.
AAC rate reducer standard buffer. (not any of the ones that require a special spring)
this is a full-auto kit, in a Colt brand model 614 RR. Full stock.
shorty upper, 5 1/2" bbl.
bbl is 22lr chambered, doesn't use the chamber insert from the ciener kit.
has run ok full mag dump a few times.
runs fine in semi. does mostly double taps in full-auto, very infrequently 4-10rds full. tried CCI mini mags, Stingers,Dynapoints. shoots double taps better with Dynapoints than anything else.
most common symptom: insert mag, chamber round,set selector to full,fire, shoots 2rds and stops. live round in chamber. hammer forward. cycle by hand, fire, get 2rds and stops, same as before.
suggestions?