Another late and probably not very helpful though -
Have you considered using a standard pistol belt for carrying your ammo and shooting? The pouch types you have fit pretty snug on a USGI pistol belt even unsnapped and don't walk back and forth very easily. I think that having the pouches on a pistol belt (even if not snapped) would be sturdier and more comfortable, and also easier to get ammo out of than the thin belt would be even snapped to it. I have a few older USGI pistol belts around here with little collector value because the markings are faded and I'll give you one of them to put an end to this if you're interested. It's very possible your pouches will snap onto a USGI pistol belt anyway because I just tested a repro pouch on two of mine and it snapped onto them just fine.
Send me a PM if you're interested and I'll be happy to send you a belt.
~ Harlan