IMR 4064 Smokeless Powderimr 4064 is the most flexible propellant in the IMR line, employed for 223 Remington, 22-250 Remington, 220 Swift, 6mm Remington, 243 Winchester Tremendous Quick Magnum, 308 Winchester, 338 Winchester Magnum, and the checklist goes on and on. Flexibility with uniformity and precision.This smokeless powder is really a smoke