Armalite DEF10 or Ruger SFAR?

[Ron3]

I've kept a couple l/r 7.62x51 Pmags loaded for a few years. Haven't cracked yet.

I dropped one, loaded, a short distance onto concrete once, didn't crack.

The number of rounds I've put through these mags is only in the hundreds though.

But so far so good.

Magazines are a wear item. Have many.

Side note:

The best AR-pattern steel mags I've ever had are the Beretta mags. All steel. Very reliable & well made. If you want steel mags, get those.