I have used the following for 7.62x39 steel, bakelite, and polymer mags.
Spiritus Systems micro fight with 7.62 insert works really well but reinserting mags sucks, you can also increase and decrease mag retention by adjusting the load in the front pouch on top of the mags.
Haley Micro works extremely well with 5.56 insert but is a little crowded but 100% workable, reinserting mags is easy with the kydex inserts.
Circle 10 3 cell rig works really well but I am not a huge fan of bungee retention, reinserting mags isn't as bad as spiritus rig but its not as easy as Haley with kydex.
Tactical Tailor AK chest rig (discontinued) is a beast, all of the above are very well made but the tactical tailor rig is probably the toughest construction of those I have tried, it has velcro flaps to protect mags if you need that kind of thing. Reinserting mags is easy on this thing but you have to defeat the velcro first so its a trade off.
Out of the above the Spiritus gets the most use for me as I have no desire or need to carry much more than one mag, ifak, and monocular. You can also pull the mag insert out, attach a velcro flap or zip top and it will hold a 75 round drum if that is your idea of a good time, dont recommend going prone on one though
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If I was to recommend one of the above to a stranger without knowing any pertinent details I would recommend the Haley micro, easy to reinsert mags, decent capacity, modular, etc.
I have yet to find a Molle solution I prefer over the chest rigs/placards above.
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