I adore my 64's...
Take it down completely, clean it (thoroughly ESP extractor/bolt face), slap the works with brake cleaner (when you're done all is very dry!). Don't oil/lube the action unless it's for storage/rust prevention. Run that thing dry!
Find an ammo that will work (As much as I adore 'em they are fussy eaters). Mine like round nosed ammo, and eat any CCI blasers(stingers n' mini mags) like candy. Federal Champions too. My favorite won't eat Winchester333/555 but others will, so it's worth experimenting.
If it'll feed n' cycle by hand, it should under trigger power too.