Yep, I concur with the seasonal (ambient temp) effects on ball powder.
A few years back I loaded some .30-'06 180 gr Nosler Partitions in front of some W760 (52.x grs, as I recall). 'Clocked about 2780 fps out of a 24 in barrel Sako. When the guy got to Colorado, he stopped at a commercial range to check zero after the drive out, and they were stringing vertically. He went and got some Federal Premiums. They shot fine and he hunted with them instead.
I can understand the impact point moving, but the stringing confused me for a while. Then I had a long range session with the guy and saw that he would get a different position and grab the rifle a different way each time he'd shoot. He was all over the paper. The problem in the cold could also have been aggravated by carrying the rounds in the heated vehicle and then taking them out and shooting them while they were experiencing a BIG thermal change. 65 degree vehicle compartment to -15 degrees outside. That could do it.
They only reference I could find in any reloading manuals to the problem was a fairly casual recommendation that "the reloader might want to try magnum primers with ball powders under some circumstances" (my paraphrased quotes).
I've also heard opinions on the effects of ball powder scooting through the throat and leade, slightly increasing the rate of erosion over stick powders. Since, with the slower burners (of either type), there is a slug of powder that gets into the barrel and burns there, there could be something to it. Whether it would be worse than the extruded powders and by how much is a subject on which I have not seen data.
www.precisionshooting.com might be a place to ask. One thing I have learned is that ball powders don't compress worth a darn. duh!
All that said, I love the way ball powder meters and I use it most of the time.