This site has done a lot for me, so I try and send the love back around....
I bought a Proximity Fuze Can, also known as the "50 Cal TALL ammo can" for storing and transporting my AR mags.... and I REALLY like it.
It can hold AT LEAST 28 LOADED 30rd Mags and a LULA. The handle on top makes carrying easy and supports the weight of 28 mags (840 rounds) nicely.
I had been using the "regular" 50 cal ammo cans for all my ammo/mag storage and transportation. It always frustrated me that I couldn't fit a lot of 30rd mags in them... and that the mags couldn't be stored vertically. Plus, they rattled a lot.
The 50 cal tall ammo can will hold 24 mags standing on their floorplates, 6 wide by 4 long, and the fit is PERFECT… very little room for rattling. More mags can be stacked on top. I highly recommend this to some one who wants to carry/store a lot of mags.
I bought mine at Cheaper Than Dirt and was very pleased with everything.
Have a good one.