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