[quote=Larfleeze]
That's not the point, the point is: Where are they going to get the equipment and supplies needed to produce shells, bullets, round etc.?
[/quote]

I think the hardest thing to find is the primer.
I cant think of a way people can make them from normal materials (You can re-use shotgun shells and make powder.)
On this note
Can I change my firearm to a musket?
The ammunition is melted down metals and the powder can be made with 'simple' ingredients ( sulfur, charcoal, and potassium nitrate (saltpeter)
Of course the disadvantages of having a musket are abundant
Cant be used when wet, crap range because of no rifling, misfires and jams, slow reloading etc.