Anyone loading magtech brass shotshells knows that you need oversized card wads as the brass hulls have thinner walls than plastic or paper hulls. Here's a trick in case your over powder wads are a bit too loose. Just put one or two waxed/lubed patches under the over powder wad, press into the hull just inside the mouth, and trim the excess patch with scissors (trimming optional). Now you have a perfect fitting over powder wad. Lubed even... 