IMR 4451 is another new Enduron extruded powder. IMR 4451 with ENDURON Technology Smokeless Powder 8 Lbs 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 favorite cartridges are covered with this fine powder. Once the shooter tries this one in that favorite cartridge, his search is over! Grain shape is extruded (stick).