I got some cheap amazon specials and put ESSTAC KYWI kydex into them and they retain very well. The mag carriers had a slick coating on the cordura so I used contact cement to glue the velcro loop to the one side of the pouch inside to mount the KYWI to. I believe I used the 5.56 KWYI, but I think the 7.62 would work as well if not better.
All in, much less than a Taco and no hard plastic digging into your side.