Thought you guys might enjoy this link to a youtube video showing a guy putting together a round for a 75mm Pack Howitzer
http://www.youtube.com/watch?v=xoMbtXMXOIw
Keep in mind - all you need to own live rounds in this country for things like anti-tank guns, tank guns and howitzers is to get the approval of the ATF - I worked with a guy in Georgia who was restoring a 57mm anti-tank gun with a live barrel and already had in his possession ten live rounds that he had to be able to show upon demand to the local ATF representative that he still had all ten of them.