Mr. Heath,
Agreed.
Here was my premise and/or assumption. In the possible social situation that started this thread, with the scenario of a semi nomadic to nomadic existence, I believe that one would be able to scrounge "usable" powder by finding, trading, etc.. Specifically in the US there are a lot of shotgun owners with shells in their homes. Not everyone who owns a firearm will be inclined to use the ammo because they may be dead, gone missing, too civilized, etc. Again, at some level (medium high to pathetic) shotgun powder can be used in most pistol calibers and rifle calibers given a little knowledge.
So while I certainly agree that in a relative short time there would be developed a localized manufacture of useable propellant and a trade/barter/transportation system coming in place; there will also be a lot of powder and primers sitting out there in unused ammunition.
There are two books that I highly recommend. The first is" Guerrilla Gunsmithing" by Ragnar Benson, Paladin Press ISBN 1-58160-119-0. This book covers many useful subjects including scrounging ammo and ammo components. The second book is "The Ultimate Do-It-Yourself Primer Cookbook" by M&M Engineering, RR1 Box 2630 Arlington VT 05250 and phone number 802-375-9484. This book is obviously self published.
Then of course the book all of us probably have " TM31-210 "Improvised Munitions Handbook" published in 1969 by the U.S. Army.
Again as I have mentioned in previous threads/posts I intend to tribal-up in a small (1-5000 population) rural based community with a deep aquifer and a paradigm of production agriculture (livestock and crops). These communities, by virtue of whom and where they are, already have a pile of guns, ammo, components and reloading equipment with the accompanying expertise. These communities are also a long way ahead in the self sufficient life.