2400 is a favorite for colder temps here too.
blue dot is affected by the cold as is h-110, and 4227 is inconsistent in the heat.
another powder to consider is 800-x it needs to be weighed individually but does well in temp swings.
also sr-4756 is a good powder ,i use it for deer hunting in my 45 colt with horn xtp's and 250 rnfp cast.
it meters very good and is pretty consistent in velocity.
i used to shoot my 357's quite a bit at distance, and i had cut out some steel silhouette's.
i was able to consistently hit these with 38 cases 4 grs of 231 and 158 swc's at a blazing velocity of @800 fps.
oh yeah the distances were from 20 feet to over 300 yds.
kinda like, bang.............................................. .........................tinggggk.
keep things over or under sonic the whole way, and look at the design for stability.
that will help more than pure velocity,and the things [problems] you need to make velocity work.