I recently purchased the Umarex Colt Peacemaker in .177 pellet. I am trying to find extra pellet cartridges or shells identical to the ones furnished with the revolver. Does anyone know if there are any available. The current cartridges offered by Umarex look very cheap as compared to the originals which are almost identical to a .357 magnum cartridge. The pellet cartridges are a few thousands larger in diameter, look like a .357, and are nickel plated.