Space beetween antler handle and guard

[Loosearrow]

I have a space th thickness of a sheet of paper between a stag handle and the guard. I am afraid the handle might begin to spin loose. There is a no way to snug it up from the back. Is there something I might be able to fill in the crack with to snug it up? Regards Loosearrow

 

[rayban]

It's happened to me too, I used a clear epoxy and mixed it with some sanding dust. I let it seep into the crack for a while then wiped any access away with DW40.
The color may not match dead-nuts when it's dry, but better looking than an empty crack.