It looks like a stamping (which doesn’t mean it’s not an engraver’s signature) and the fifth letter is obscured by the engraving. And btw, thanks for posting a nice, clear closeup. Sometimes people post pics that look like they were shot from a satellite on a cloudy day. You can barely identify the make and model, let alone the engraver.
The name of that engraver is unfamiliar to me however, factory engravers at the FN factory stamp their names in that way and, often, in that location. I have checked the list of well-known FN factory engravers and no similar name is there.
Perhaps, Rocco Capace will chime in. If anybody knows that engraver he will.