I'm certainly not saying changing out ammo is a waste but I have shot ammo that was at least 50 years old and it fired just fine. Before my dad passed away he had some 300 H&H mag and 38 specials from the 50s tucked away in an old chest. Each one of them went bang. Now if ammo gets wet that's a different story. I imagine there are as many opinions on this as there are on open/concealed carry.