We recently wrote about Bulldog’s Mortar and Machine Gunner’s Packs. The Mortar Pack already has a SOCOM NSN and the patent pending Machine Gunner’s Pack is in testing with several organizations.
Here are the ammo carriers which each accommodate up to 300 rounds. Additionally, this system saves 3.5 lbs off of a standard barrel bag and the system can fit any pack. This one is mounted on an ALICE frame.