Rifle Magazine Pouches http://www.militarymorons.com/equipment/emdom2.html#mmc
This company states their .308 pouches accommodate Magpul Pmag 20LR mags. They offer a flap-less single mag pouch, a flapped double mag pouch, and a brandolier type belt that holds 8 20 rounders. Here's the bandolier's description:
The Emdom/MM 308 Modular Magazine Carrier is designed to carry 8 standard 20 round .308/7.62x51mm NATO magazines (FAL, SCAR-H/Mk 17, M1A/M14, SR25, M110, Magpul PMAG 20LR, etc.) on the inside or outside of a MOLLE/PALS compatible rifle case. It is also designed to be used a stand-alone bandoleer/chest rig. With the shoulder and waist straps removed the 308 MMC can be mounted to an armor carrier or other MOLLE/PALS platform via the included set of 4 long MALICE clips.
Sorry for not having experience with it.