Solution Overview: IMR 4227 PowderManufacture of IMR powders dates back again in excess of 200 years when the business was originally Established by E.I DuPont. Obtainable for use in lots of reloading purposes, the IMR series of powder is trusted by reloaders all around the world.IMR 4227 Powder in stock now is the Magnum Pistol Powder from the IMR