This scene got points for creepiness and atmospherics, but for a gun nut it was pretty annoying. Bullets aren't hard; a lot of people cast theirs, and you don't need to re-use old bullets. Back in the day, you'd see the gun nuts hitting up their friendly neighborhood mechanics for discarded lead wheel weights. Melt 'em down, cast 'em, by god you've got cheap bullets. I knew one guy who did a lot of re-enactment stuff who would use old roof flashings; apparently they used to use lead for that. Anyway, the catch is the other stuff: primers and powder. I figured the biggest problem would be the primers; reloaders buy those intact, so how would you make your own?
Well, with the recent extraordinary rush on all manner of ammunition and related materials, some folks on the gun boards have started talking about that very thing. It seems that you can take the primer apart, fix it up, and re-prime it using powdered strike-anywhere matches. I even found one enterprising guy who is *firing his guns* using match-head primers *and powder.* The match-head powder is corrosive, so you have to wash the gun with water and clean it well after shooting, and the ammunition is underpowered; he says that it makes a .357 Magnum shoot like a .38 S&W, though he could probably get it up to .38 Special. But it is physically possible (YouTube instructional link).
Incidentally, if strike-anywhere matches are too hard for you to get ahold of -- I didn't know this, but apparently they're restricted some places -- you can make your own from regular matches.
Useful gimmicks for anybody who might wind up writing post-apocalyptic stories, or freedom novels.