I recently took a plunge and bought 8pounds of 4451 which is one of the Enduron powders from IMR. With a burn rate similar to 4350, it should be perfect for the cartridges in which I would normally use that powder. We shall see. Relatively fine grained so will meter well. Also, it is denser than 4350 so in those cartridges where capacity was borderline for 4350, this might be good. I would think it should pair upwell with 80-85 grain bullets in the 243. GD
