The AD-52 is a fairly common weapon for various inhabitants of the Wondernations. It "deals" or shoots out fifty-two razor edged playing cards with each shot. Ammunition apparently comes in a deck form similar to a cartridge.
In The Looking Glass Wars, a group of cut soldiers is said to be armed with AD-52's, so it is possible that they have only been invented in the first book.
In a schematic provided in ArchEnemy, an incendiary version of the standard razor edged amunition is shown, but as it was never used in the trilogy, its effects are unkown.