AR-15s
Mike240 mag advice was spot on, we load 28 in thirties as well. Some get stored for multiple years, no issues. By no means not best practice just reality. The only thing I would add is we number our mags. In this way you get a malfunction of any kind you document mag number. Moving forward you create empirical data or history if you will on the mags. And in addition it makes inventory much easier. You get a repeat offender mag you toss or rebuild.