It would be a good idea to clean the chamber thoroughly and frequently. I shoot .44 magnum revolvers occasionally with the shorter .44 special, and likewise the .357 magnum with .38 specials. I will notice the longer magnum cases are stiff loading in a dirty cylinder after shooting the shorter specials. I have not experienced this with the .458 lott, but as I stated in the beginning, It seems like a good idea. I do it with mine. An ounce of prevention...