........and if the SR25 bolt carrier group is usable, then as far as I know the Fulton Armory BCG should be compatible.
If the Fulton BCG is compatible, then the DPMS is also compatible.
If the DPMS is compatible, then the Armalite is also compatible.
I wouldn't be surprised to learn that LaRue's will also work.
That should give lots of options.....which is great in my book.
