Manufacture of IMR powders dates again over 200 yrs when the corporate was originally Started by E.I DuPont. Obtainable for use in several reloading applications, the IMR series of powder is trusted by reloaders all across the globe.IMR 4227 Powder in stock now could be the Magnum Pistol Powder within imr 4227 the IMR lineup. If it states Magnum, 4