I've found that I really need only one factory mag for my .45; I use full-length 7-rounders as reloads. I try to take really good care of the factory mag, and use the more plentiful mags for rough duty (ejecting onto the ground, etc.). That doesn't help you find additional factory 9mm mags, but at least you can use Metalform or Colt mags until you find additional Detonics mags.