Has anyone ever removed a low pro gas block on a BCM before? I’m trying to change out my rail system and I can’t get the set screws out to save my life. I’ve came to the conclusion that its gonna take a propane torch to heat it up but does anyone have any other tips that would be helpful? And also, does anyone know that exact Allen size for the set screws? Any help is greatly appreciated.
You sure you’re turning the correct way? I did that yesterday 
I had put mine on myself with blue thread lock and it wasn’t that hard to remove. I can’t imagine they are using anything stronger than that.
A propane torch is the way to go. Put the heat right on the screw. I’m not sure about the allen wrench size, just make sure you use the one that is most snug and that it doesn’t seem loose after the screw is heated up. I’d do it with the barrel in a vise and use a hammer to smack the allen wrench until the screw breaks loose.
Ok we’ll ill just lay the heat on it and hope for the best. Surely it will be enough heat to loosen them up. I know BCM uses some time of super high temp locktite so hopefully it gets hot enough.
Use the search button… This has been covered and the thread can help.
https://www.m4carbine.net/showthread.php?t=113258&highlight=BCM+GAS+BLOCK
A new thread is frowned upon.