Not necessarily, Loaded ammo over time can allow humidity to migrate into the powder. Leaving powder in sealed containers and using humidity control in your reloading room makes a huge difference, I keep my Reloading room around 45%. I've noticed muzzle velocity disparity of 30 fps from ammo that was loaded 3 weeks prior to ammo loaded on the day of, When shooting 2500 yards that makes an astronomical difference in vertical stringing.Maybe it makes a difference if you have a rifle that can shoot in the 1's. That eliminates 99.9% of us.