Howdy, Pard,
Doeskin is probably too soft and chances are it is chrome-tanned, which is tough on cartridge brass! If you want to use this to cover the buttstock, and presuming the finish pretty well seals the wood of the stock, you might want to make a rectangle of topgrain cowhide to which you stitch the cartridge loops, also topgrain cowhide. The rectangle can then be attached to the doeskin by stitching. The cartridge carrier should be on the side of the stock opposite your cheek!
Hopes this is of some help!