MR 4166 is a versatile, match-grade propellant, with the fastest burn rate in the Enduron line. It is an extruded powder with a perfect burn speed for cartridges like 308 Winchester, 7.62mm NATO, and 22-250 Remington. IMR’s Enduron series features a Copper Fouling Eliminator to keep you shooting longer without clean up. They are also insensitive to temperature changes. In addition, they provide ideal loading density and being environmentally friendly. This propellant performs comparably to Hodgdon Varget but charge weights are materially different.
IMR has data available utilising this powder for .204 Ruger, .223 Remington, .224 Valkyrie, 22-250 Remington, 6 Creedmore, .243 Winchester, 25-06 Remington, 6.5mm Creedmore, 6.5mm Swedish Mauser .270 Winchester, 7.62 x 54R, .30-06, .308 Winchester, .303 British and even .45-70 Gov’t.