OK, has anyone ever taken the FSB off of an M&P 15? Mine has been a royal pain in the butt to remove; the taper pins aren't budging one bit, even after making some cheesy sight blocks out of wood to try to hold it steady and covering the area of the pins in WD-40. I need it removed so I can chop it down and install my Troy TRX Extreme 13" rail (So please don't suggest buying a $35 Brownells polyethylene sight removal block, I could just have my local gun shop do the whole install for $50). I think I'm doing everything right, hitting on the small side of the pin. Please help!