IMR 4064 Smokeless Powderimr 4064 is the most versatile propellant within the IMR line, employed for 223 Remington, 22-250 Remington, 220 Swift, 6mm Remington, 243 Winchester Super Small Magnum, 308 Winchester, 338 Winchester Magnum, and the record goes on and on. Versatility with uniformity and accuracy.This smokeless powder is a smokeless medium