Whats the crap around the mount pin. The pictures not vary good, it looks like rust. On all other M4s I know they just use a pin to hold the sling mount to the front sight. You need to just knock it out. Same with the two pins that hold the front sight to the barrel. Use the right sized nail or small screw driver or something with a hammer. Dont need to bang them out hard. Just light taps should push the pins out.
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