Has anyone seen this shell before ?, as I sure haven't. The base is iron and the thin rolled brass casing is very different. I have found the much thicker full brass Winchester cases before, and a few huge 4 gauge market gun cases, but these are a first. The base looks to be 16 or 20 gauge. I dug up about 30-40 of them then tired of it. The soil in this one spot is polluted with them.