There are uses for bandoliers, whether everyone here agrees about it or not. The entire idea of issuing Soldiers ammunition in bandoliers is to avoid them having to carry a large load of magazines, which are more expensive and bulkier than bandoliers full of rounds.
OP, if you want to pack your loose ammo in bandoliers,
Old Sarge can help you out. Repack kits can be a crap shoot, but Old Sarge has always been reliable and good to deal with.
On the other hand, unless you're going full tilt Rambo, it may be easier and more practical to just pack all the rounds on stripper clips, instead of adding in the cloth bandoliers and cardboard sleeves. Then sit down and practice loading magazines with stripper clips; it's not as trivial a task as it seems, until you get the hang of it.