You are correct, the Riggers pouch will work. What I use to carry my high-caps is actually some type of surplus European (French or German) 4-cell sub-machine gun magazine pouch that I picked up at Army Barracks for all of $3. Its incredibly durable, holds the mags tightly (which makes quick reloads difficult, but not impossible), and didn't hurt my wallet. Unfortunately, I have no idea what its country of origin is (tag said French) and I haven't seen another one at Army Barracks...