I wouldn't be afraid of the barrel life in the 22CM, they make barrels every day of the week! In fact they might be making some right now. Plus, once you have your load development down, and keep range sessions reasonable, some hunting trips every year, how long will it really take to burn out that barrel? Maybe a couple years, so buy two or three barrels at the same time and have them all fitted the same and swap them out as they get well done.