The Nashville Arsenal, and the 6th Mississippi, were among the first recipients of imported British military goods.  The Nashville Arsenal files shows the accoutrements to have been white buff leather Line equipment.  Made by Merrick's Custom Leather, this cartridge box is copied from an original and includes a tin, maker stamp, and inspector stamp as per the original.  A white buff box belt is available separately.  

British Cartridge Box - Shiloh