I also recently installed a Troy Alpha Rail on my BCM 16" LW Mid-Length. Mine is only a 9" and I love it. Very solid rail that locks up really nicely. Very good locking mechanism.

You do not have to remove the factory barrel nut which is a huge plus. I did have to remove my flash hider since I've retained my FSB.

Very simple -- Removed hand guards, removed flash hider, removed FSB/gas tube, slid the Alpha Rail on, put the gas tube back in place and lined up my FSB properly.

Honestly, installation of the Alpha Rail will take maybe 10 minutes aside from aligning the gas tube and FSB which is always a pain in the ass for me.

Nice write-up!