Yes, nowadays Hornady does make most of their own brass. Wasn't always so. When they first started out, they reloaded cases like military 30-06. Later they started loading Federal- and Winchester-made FRONTIER-head stamped cases. Of the types I've been able to identify, they also used HORNADY-head stamped cases made by S&B (Sellier and Bellot of the Czech Republic), Starline, Remington, Jagemann, and possibly by Arms Corporation of the Philippines, in addition to two suppliers I haven't identified. If Hornady sells empty brass cases, they are making them in-house. Hornady does not resell HORNADY-headstamped cases supplied by other companies as components. Probably written into their supplier contract to prevent Hornady underselling their supplier. Anyway, that doesn't mean Hornady can make all the cases they need in-house and may still have to go out and find suppliers. The latest steel-case HORNADY-head stamped 9mm LUGER cases, are from Bosnia, for example.