Chances are they will fire just fine. I have fired ammo that has had all kinds of corrosion on it, just to see if it would fire. (Always clean the gun very well afterwards.)
I would get another box of ammo (I like the idea of the nickle plated ammo if you are not shooting it very often) and switch out the old rounds for new one.
Again, the chances are the rounds would fire, but if it is your personal defense weapon, why take the chance.
Inside Every Bright Idea Is The 50% Probability Of A Disaster Waiting To Happen.