link...I reached out to several big-name ammunition manufacturers while conducting research for this article, and the only specific guidance I got was this: you should rotate your duty ammunition every six months....If your gun is a pure home-defense tool that doesn’t get cycled that much and rarely leaves a climate-controlled environment, you can safely extend that number to a year or more.
It's a good idea to periodically shoot your carry gun/ammo combo to insure that you #1 get practice with it, and #2 have complete confidence that everything is working properly.