I use a old load bearing vest. I can fit a total of 24 tubes in the four mag pouches and way more then enough 12grams in the grenade pouches.
I have also rigged a hydration pack to the back. I also use a shot gun belt around the bottom of the vest that i attach my dump pouch to.The whole set up is a bit heavy and probably overkill.
This is what I got.. I will have to get a pic of my exact set up