Santo: A very economic option to brass ferrels is as close as your nearest building supply.
I've seen some really nice tool handles with common copper pipe ferrels.
Or most plumbers have piles of copper pipe around, though scrap prices are way up right now.
Ordinary hardwood dowel rod comes in various diameters, and yes a couple of them are a pretty close fit for different cartridge cases... Stain the wood, put on as nice a finish as you wish. Cheap.