With the massive temperature swings in Manitoba, I like powders that are stable. I've avoided any ball powder, and typically shoot Benchmark or 8208 depending on bullet weight. Both of these are fine grained stick and meter decent, I have a non-max load with a 69gr TMK that I load on a 550 that holds easy sub moa from an SLR at 600.
If you go with ball powder, do some testing in both hot and cold, but beware of working in the max range if the load is developed in colder temps and it gets hot. Even a heat soak in a hot chamber can cause a spike.