[L.S.J.S]

well when I got mine.Before changing anything! out of the box I fired about 100 rounds and it jammed up. I took it apart and the piston head had come loose. The screw holding it to the piston was loose causing it to lock up. This has happend to many of these guns. so I suggest checking that out when you get it. All you gotta do is put some thread tape or lock tight on that screw and tighten it up other than that. Your good to go.Any TM compatible front end will work just make sure you get the inner barrel that fits.And whether you change to something as short as the dragon or as long as the m4 your internals should be fine mine were. I upgraded them anyways but you wont need to.just tape up that screw : )If you have any problems doing all this let me know I would be happy to help......................