Originally Posted by
dakotalawdog
Sure you wouldn't rather go with a low pro style gas block? It can be a bit of a PITA to punch out the taper pins, but with a big hammer, some heat and punches, its probably easier than grinding down a FSB. If you don't want to dimple the barrel (BCM sells a slick tool for that), you can pick up a clamp on style DD gas block. I've used several, they work great....
also... if your FSB has bayo lugs, be sure to grid them off too, if you want to mount a rail on the bottom of your hand guard.