Very common on the "new" (Pac Bay style) Sabres. The tip is a half sized one, about a 7-1/2.
You could try a few things. You could cut the tip back slightly so it takes a full 8 snugly, if the rest of your guide spacings aren't too affected. You could build up the tip section with thread. Or you could try what the guy at #^&#^&#^&#^&'s Tackle on MV did when my "Sabre by Pac Bay" (since sold) had the same problem--he scraped some of the gelcoat off, saying this would allow the glue to get a better grip. It worked, at least for the remainder of time I owned the rod. Of course, the net effect was that he may have reduced the size of the tip enough that a size 7 then fit
