**A full-auto (A.K.A. M16) bolt carrier installed in a standard semi-auto AR-15 will not make the gun fire full-auto.
Do you have the BCG inside your AR-15 that you really want? Some people don't care, just as long as it seems to work. If you're running a carbine-length, straight AR-15 with standard ammo, I guess it really doesn't matter. However, if you have an SBR or you like to run your gun suppressed, the BCG inside your AR does make a difference. You need a BCG designed for your particular gun.
Up till now, if you wanted your SBR or suppressed AR to run, you had to use an M-16 BCG. While that will run, it results in more recoil and stress on your weapon. The CMC AR15 BCG carries more mass than the standard BCG and less than an M-16 style. This design is ideal and proves a perfect match for an SBR or suppressed AR-15. The CMC AR15 BCG adds just enough mass to increase your guns dwell time to cycle right and extract that brass every time.
CMC carved its niche in the shooting world with its premium triggers. No intelligent conversation regarding AR-15 trigger groups will come up without CMC being in the middle of it. CMC brings that same made in Texas trigger mastery to their 300 Blackout BCG. After all, the BCG is the heart and soul of your AR. It has to be right. Every 300 Blackout BCG that CMC creates has to be perfect, or it doesn't leave. You want a BCG to be as slick as possible. Every CMC AR15 BCG is CNC ground after heat treat. They add a Black Nitride finish, High-Pressure Testing, and Magnetic Particle Inspection, and you get excellence.