It can be changed into whatever configuration you want, but right now I'd get some time running it like it is and see what (if anything) you actually feel that you need to change. The first one I built had a FSB/magpul handguard set up and I soon decided that it had to go, because all the cool kids had free float. That's a poor reason to change what I was already happy with, but it was my first one and I wanted to be cool too ??. I still think about building another one in the original configuration. There's something to be said for a simple, basic rifle and shooting m193 you're not going to notice a benefit from free floating. I'm not saying dont do it. It's your gun. Get some time on it before you make changes though and see what will actually be a benefit. I'd look at upgrading the trigger before spending the money an a rail.