I have a Bushmaster ORC 16in. It seems that Bushmaster/YHM has discontinued the optional front sight that can screw over the low profile gas block that comes with this rife.
In a earlier post I was thinking about getting Troy Industries BattleRail TRX Alpha Rail (11-Inch). Will this fit over the stock Bushmaster low profile gas block? How difficult would this installation be, does anyone have experience with this upgrade?
Thanks in advance.
Awesome rail, however you will have to remove your bayonet lug and sling mount with a dremel. Or you can buy a lp gas block but the cut down fsb is the best choice.
Thanks for the quick reply. As far as removing the old cylindrical free-float hand guard, does it screw off. I am guessing the Troy will come with it’s own mounting hardware to replace what Bushmaster has?
I am just trying to get a gauge on how hard this install would be. Cutting down the sling mount should not be an issue. Just unsure on current hand guard removal.
I think your set up has the YHM rail that screws onto the large aluminum barrel nut. You will need a YHM wrench to remove the rail and in some cases they can be so difficult that you will need to simply cut it off.
It can be done with a little patience.
Doesn’t sound reassuring 
As far as the tube goes, that can just be unscrewed with a strap wrench. The actually base will need to be removed with the YHM tool you mentioned?
Attached is a pic of tube/handguard, mine is just a shorter version.
Ours were different. They were YHM ventilated rails that used the large aluminum nut and the locking ring nut. You shouldn’t have too much difficulty in removing it or the FSB.
I would heat it up first (nothing crazy) and then apply some lube to the pins to soak.
Actually would it make more sense to just get a YHM rail to replace the tube with. Could it be as easy as unscrewing the old and screwing in a new rail with the exception of grinding down some of the front gas block?
Not quite. YHM rails run on the hefty side, and their dimensions aren’t known to be held in close tolerances.
Your initial instinct with the TRX is a good one.