IMR 4451 with ENDURON Technology Smokeless Powder 1 Lb is another new Enduron extruded powder. IMR 4451 with ENDURON Technology Smokeless Powder 1 Lb gives top performance in the venerable 30-06, 270 Winchester and 300 Winchester Short Magnum, to name just a few. This propellant is ideally suited for many, many mid-range burn speed cartridges. Simply scroll through the list of cartridges on the Hodgdon Reloading Data Center, and see how many of your favourite cartridges are covered with this fine Enduron reloading powder. Once the shooter tries this one in that favourite cartridge, his search is over! Grain shape is extruded (stick).