Manufacture of IMR powders dates back over 200 many years when the company was initially Launched by E.I DuPont. Available for use in lots of reloading purposes, the IMR number of powder is trustworthy by reloaders all across the globe.IMR 4227 Powder in inventory now is the Magnum Pistol Powder while in the IMR lineup. If it suggests Magnum, 4227