You don't have to anything to your mags other than just shoot. Loaded, unloaded, doesn't' matter.
Most guns tend to shoot better with loaded mags.
I had read somewhere about taking the rounds out and then reloading, but didn't see the point of it.
Thanks Tulse.
I find the best way to break in new magazines in to start about by buying a case of ammo. Then head off to your favorite shooting spot. Load the magazines insert into gun shoot until all mags are empty. Repeat until the case of ammo is depleted.