I use Super Lube clear synthetic, year round. In winter I'm test firing rifles in temps from +5C to -30C and no issues. I first started using it years ago in my fishing reels, both winter steelhead and runnin charters on the west coast , both extreme conditions and that grease excelled in icy and corrosion rich environments. Started using it on firearms som 10 years ago and it's still number one for me 
Lot's of greases do the job well and a person doesn't have to be too fussy on what brand is the "best lube" . My wife says the cinnamon flavoured body lube is the best.... But that's for a different weapon altogether
Lot's of greases do the job well and a person doesn't have to be too fussy on what brand is the "best lube" . My wife says the cinnamon flavoured body lube is the best.... But that's for a different weapon altogether