I was wondering how hard it would be, if its possible, to cut a notch out of a M4A1 RIS II rail for a midlength FSB? Just like the carbine version but for a middy. I wanna build a 14.5" middy using a RISII but I wanna keep the FSB intact. Thanks
A competent machinist would be able to do it. Not something I would attempt with a dremel in the garage though.
If that option doesn’t suit you, there are other hand guards that allow you to retain the FSP, but you didn’t ask that, so I’ll shut up now.