Product Overview: IMR 4227 PowderManufacture of IMR powders dates back above 200 decades when the corporation was initially founded by E.I DuPont. Readily available for use in many reloading apps, the IMR series of powder is dependable by reloaders all across the globe.IMR 4227 Powder in inventory now would be the Magnum Pistol Powder within the IM