I haven't seen this and could use some assistance. My rifle doesn't have any sling mount studs and I was wanting to install some. Before I predrill I want to clarify that there isn't already something that would work. It has recessed notches that looks like a nut down inside of them. Does this get removed to put in a sling mount? Do the sling mounts get installed in the holes provided after drilling? It is an FN SPR.