Here's an old AskHistorians answer from /u/backgrinder concerning the long and difficult effort of Henry V to amass enough arrows to supply his campaigns in France, here's one from /u/WARitter dealing with how many man-hours were required to produce a suit of chainmail, here's something from /u/wotan_weevil on how it could take years for the wood to be fully seasoned and the glue to dry on a Bronze Age composite bow, here's something from /u/Iguana_on_a_stick about the logistical difficulties of raising and equipping large numbers of Roman soldiers to replace those lost at Cannae, and something from /u/WARitter again about large-scale production of plate armor.