IMR 4064 Smokeless Powderimr 4064 is the most adaptable propellant within the IMR line, used for 223 Remington, 22-250 Remington, 220 Swift, 6mm Remington, 243 Winchester Tremendous Small Magnum, 308 Winchester, 338 Winchester Magnum, as well as list goes on and on. Flexibility with uniformity and accuracy.This smokeless powder is a smokeless medi