I use my old 5.11 tactical stacked double AR mag pouches to hold 2 side by side (bullets facing outward from body) in each pouch. It holds them quite nicely. An elastic band helps hold them in the pouch so I can tuck the covers inside and not have to f**k with it when I need a fresh mag. 99 rds to dispatch the hoards of squirrels, beavers and hookers and 1 rd for me in the event I fail. For lil bit shorter mags they make a flash bang pouch with the same dimensions except a little shorter. I can snap a few pics if you want.
Mag pouch
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Flash Bang pouch (same as mag pouch but shorter)
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