I recently acquired a Professional Ordnance carbon 15. Don't really know anything about this particular weapon. It has been sitting in a closet for a good while the guy that gave it to me said it split the gas tube and he replaced it . Afterwards he put it back together with a new gas tube and then it became a single shot. My question is has anyone had any experience with this early bushmaster carbon 15? Are there any parts available? Any help at all is appreciated.