IMR 7977 with ENDURON Technology Smokeless Powder 8 Lbs is a slower burn rate in the Enduron family, and is a true magnum cartridge propellant. It yields outstanding performance in such cartridges as the 300 Winchester Magnum, 7mm Remington Magnum, 338 Lapua and a host of others. Loading density is perfect for magnums, nicely filling the case at maximum charges, contributing to superb uniformity and accuracy. The 7mm Remington Magnum “never had it so good”! Grain shape is extruded (stick).