More than two centuries have passed since E.I. DuPont established the company that would become known for manufacturing IMR powders. The IMR series of powder is widely used and trusted by reloaders around the world. Key characteristics of the Enduron series include a copper fouling eliminator, resistance to temperature fluctuations, optimal loading density, and low environmental impact. Check your scope when it’s 100 degrees outside, and load your tag when it’s freezing. IMR 4451, another Enduron Technology extruded powder, provides outstanding performance in a wide variety of cartridges, including the time-honored.30-06,.270 Winchester, and.300 Winchester Short Magnum. There are a great deal of cartridges whose optimal burn speed falls somewhere in between, and this propellant is perfect for them.