I'm not sure if these subjects fly around here, but even if you ignore the zombies you can maybe imagine a situation of hardship where you may need to cast and fire boolits without proper equipment.
An obvious source of lead would be picking off wheel weights of all the abandoned cars along the road. Melting them could be done with a campfire and pot.
The mould seems to be a hang up. What would you guys use? Something out of clay? Kitty litter perhaps? Maybe a wood mould? I think I'd just make a long tube of lead then cut it into sections. From there I figured I could knurl the lead boolots by rolling it on a steel rasp with some pressure then tumble it with some crunched up pencil lead for a crude lube.
Powder would be the holy black since it seems to be the easiest to make.
Primers could be reformed and filled with match heads. Cases would stay fire formed and be crimped back with pliers. I think this would work with a revolver.
Anyway, I thought it would be fun to come up with a strategy with the TV show coming back this month.