Is the play side to side or up and down? And how much play is there? Can you actually see the blade moving?
Some of my 110's do display a very small amount of side to side play, but none up and down. The play that mine exhibit can only be felt as the actual blade movement is too small to be seen. I'd say this is normal since there has to be a little clearance for the blade to open smoothly. Some are just made a bit tighter than others, which would account for the roughly 50% of mine that do not have any felt side to side play. And none of my 110's have been used much, just opened and closed.
On the other hand, if it is up and down play, then I would suggest you send it in to Buck for repair. One thing to check for first would be foreign matter (dirt or pocket lint) in the locking area of the blade.
Hope this has helped some.
------------------
Dave Fortman
~Buck Collectors Club~
~Lifetime Member #736~