I just got back from the range. It might have been an expensive trip! I shot my defense ammunition. At least two boxes. Some of it has been in a magazine for over a year. These are the kind of things I want to know. I want to know if my defense ammunition is good to go. I want to know if it will be there for me when I need it. So should you! Defense ammunition brings more potential issues to the equation of your gun going bang. Jacketed hollow points and the like are jagged and do not have symmetrically round noses like what people use for training (full metal jacket). They could present an issue feeding. So the worst thing to do is buy a box of ammo, load up a magazine and never shoot it. But you are carrying it. Yikes! Do not setup yourself for failure, shoot a box or two of your defense ammo with the same magazines you will use for concealed carry or defense. Do not leave it up to chance.
I go one step further in my training. I use Federal HST 124 +p defense ammo for my Glock 19. When I train I use Winchester 124gr NATO ammunition. The NATO means it is higher pressure than standard. So I am training with something very similar in weight and pressure as my defense ammo. If you shoot your gun with a 115gr or 147gr standard pressure you might be getting a different result. Limit chances for failure. Train like you fight and shoot your damn defense ammo. Your life depends on it!