Factory made hand loaders are nice and convenient. If you want a real custom made handloader that is cheap, portable, and consistent, build a reloading jig out of hardwood planks, dowels, a couple nails, and a couple dremel bits, and forget the dies. Use a drill press and a set of micrometers and a pre-loaded round or two to help build the jig to your specs and you can build quite a nice field loading kit that will always load consistently and reliably.

Of course, for the ultimate field reloader, buy a muzzleloader and leave the cartridges at home.