Jewelling is only a fancy polishing (if done properly) and readily wears, no affect whatsoever on what the barrel is. Be sure the barrel is properly cleaned and scrubbed, and all copper residue removed. Amazing what a thorough cleaning will do. Are you sighting it from good padded rest? Quality ammo? Action, scope mounts and bases properly tight? Quality scope? No caffeine before shooting?
Many things add up to accuracy, and all need to be proper before a call can be made the gun isnt accurate.