portions of the shotgun shell, as well as in their dimensions. Card wads, made of felt, leather, and cork, as well as paperboard, were all used at various times. Waterglass (Sodium silicate) was commonly used to cement the top overshot wad into these brass shell casings. No roll crimp or fold crimp was used on these early brass cases, although roll crimps were eventually used by some manufacturers to hold the overshot wad in place securely. The primers on these early shotgun shells were identical to pistol primers of the same diameter. Starting in the late 1870s, paper hulls began replacing brass hulls. Paper hulls remained popular for nearly a century, until the early 1960s. These shotgun shells using paper hulls were nearly always roll crimped, although fold crimping also eventually became popular. The primers on these paper hull shotgun shells also changed from the pistol primers used on the early brass shotgun shells to a primer containing both the priming charge and an anvil, unlike rifle and pistol ammunition, making the shotgun shell primer taller. Card wads, made of felt and cork, as well as paperboard, were all used at various times, gradually giving way to plastic over powder wads, with card wads, and, eventually, to all plastic wads. Starting in the early 1960s, plastic hulls started replacing paper hulls for the majority of shotgun shells and by the 1980s, plastic hulls had become universally adopted. Typical construction Modern shotgun shells typically consist of a plastic hull, with the base covered in a thin brass or plated steel covering. As noted previously, paper shells used to be common, and are still made, as are solid brass shells. Some companies have produced what appear to be all-plastic shells, although in these there is a small metal ring cast into the rim of the shell to provide strength. Often the more powerful loads will use "high brass" shells, with the brass extended up further along the sides of the shell, while light loads will use "low brass" shells. The brass does not actually provide a significant amount of strength, but the difference in appearance provides shooters with a way to quickly differentiate between high and low powered ammunition. The base of the shell is fairly thick to hold the large shotgun primer, which is longer than primers used for rifle and pistol ammunition. Modern smokeless powders are far more efficient than