To make the background story short, I have a Combat Machine M4, and I bought a RIS unti with extended rails (which means the rails pass the front sight post). Before buying this I failed to realize that on the CM M4 the front sight is welded on and not held on by pins (Like the Echo 1/JG series).
So this leaves me in a dilemma, what parts do I need to actually get to fit on my M4? I already know I will need a new outer barrel (obviously), which outer barrels are the best for this kind of project for those with experience have figured out?