I actually went with a much simpler method..... more to follow when I can dig out a sample. But in short, I did not vacuum pack due to info I had at the time. I have a largish case...or so... of loaded P-mags ready to go. When I moved last fall, everything was inspected and found in perfect order, with no issues. Probably should do a test fire just for giggles.
The ww2 reproduction ammo boxes came in and I used most of them and they work great. Pack real nice in a 50 cal ammo can.
Well I needed some more ammo boxes. I mined thousands of 223/5.56 cases from the local shooting pit. Lots of cleaning, sizing, depriming, more cleaning, trimming, deburring, more cleaning, sorting then loading. You can find wolf and tula 223 boxes dirt cheap since there's no reason to keep them, cause the cases are steel.
I get free empty ammo boxes from the nearby indoor shooting range, always get some 9mm, a few 223 and maybe something else if I'm lucky like a 45acp or 38spl.