I have a mkIII 22/45. I put about 300 rds in it yesterday and it locked up on me. I oiled the hell out of it and it is working great again. I havent tried to field strip it for the reasons mentioned above. Has anyone else had jamming issues. I think it may be because the bolt wasnt oiled enough but my ammo gets jammed a lot when it is trying to get jacked into the chamber. Almost all ammo has done this.
I have had my mkIII 22/45 hunter have problems fully ejecting shells after extended shooting sessions (200+ rounds) w/out cleaning. Basically the shell will eject but the bolt starts to close as it is ejecting and the bolt tries to close before the empty shell has fully cleared the chamber. It only happens when the gun starts getting really dirty and I can feel the grit building within the gun.
Your train of thought is correct though- a few drops of oil on the bolt will usually keep it going jam free for another few hundred rounds, but eventually you need to fully break the gun down and give it a good cleaning.