Absolutely !Why is one storing ammo/ammo cans in a safe? I've got a few boxes of HP's in mine, but I've never "stored" ammo in any container in the safes.
As Rick mentioned, it's easier to grab a handful of loose rounds from one of my ammo cans when loading mags. Also been using an UpLula [ have 4 actually, one double stack, one single stack, one 22lr, and some other one I forget what it's made for ] for the last 2 decades. Nothing beats the Uplula's I've ever tried for mag loaders.