This cartridge was developed by JD Jones that actually started out as the 411 Whammy. Reason being that at that stage there were a good variety of .411 cal bullets available in the US as opposed t the 416. With the resurgence of the 416 Rigby, quality bullets became available and the 411 was necked up to .416 and originally called the 416 JDJ. Ballistic tests however showed that a rimmed case would have much better extraction in a T/C barrel and therefore the 416 JDJ now uses the 444 Marlin case as opposed to a belted case.