Most likely a piece of garbage. It's got the same gearbox in it that deuce dropped in his M4 and that thing just came with so many problem, the gears in it weren't even able to function in the gearbox they were to big, and the trigger mech is funky. The body is a matrix metal body...the whole gun is just ehh...the tightbore is probably garbage too, it can be 6.04 diameter but its the consistency and smoothness of the bore that determines how good a tight bore is.
If you're not stuck on an M4, perhaps you should look at the CYMA AK series, those things are fricken awesome, you won't even need to upgrade it out of the box. Mines shooting 420 FPS with .2's out of the box, and from what I have seen on the inside...nothing really needs to be replaced, I just split it open to give it a nice re-lube and re-shim like I do with all my new guns to make sure everythings working properly before I take it to a game.
