Manufacture of IMR powders dates again about 200 yrs when the business was at first founded by E.I DuPont. Readily available for use in several reloading applications, the IMR series of powder is trustworthy by reloaders all around the world.IMR 4227 Powder in inventory now may imr 4227 load data be the Magnum Pistol Powder during the IMR lineup. I