I use IMR powders in all my center fires. the IMR 3031 is what I use for the 308 and soon the 220 swift.
IMR 4350 in the 243, 7mm08 and the 300 win mag.
Have been youte hunting in well below zero weather all winter with the swift loaded with IMR 4064 and it has worked even at a wind chill of 28 below. Windy days used the 243 and it didn't miss a beat either. Been a lot of windy days this winter along with the cold & snow .
Al