Are you shooting reloads or factory?
What type bullets are you shooting? 200 or 230 gr? Ball, SWC, or RNFP?
My 97 is VERY picky about OAL of its cartridges. Seems to like longer better than shorter. If you are not shooting 230 gr. ball (factory), give that a try. If you are, a trip to CZ for your gun is probably in store.