I tend to stick with ammo that comes with sealed primers, and am very careful to keep the breech face and chamber dry after cleaning. Never had a problem. That said I may have to adopt some schedule for carry ammo replacement. I also test fire a sample from every lot number before I accept for carry. During past ammo runs quality fell, and lot number tests identified a bad lot that was replaced by the manufacturer. Basically I shoot a box of 50 from a lot in a specific pistol and call it good.
Before retirement I had to do a quarterly LE qualification. We almost always shot up our carried service ammunition right off the bat for practice, and then we qualified with service ammo. So every three months we had new service ammo to carry.