Product Overview: IMR 4227 PowderProduction of IMR powders dates back more than two hundred decades when the company was at first Launched by E.I DuPont. Accessible for use in many reloading purposes, the IMR series of powder is trustworthy by reloaders all around the world.IMR 4227 Powder in stock now will be the Magnum Pistol Powder within the IM