Never ever once had any problems with Blue Dot powder, and that is over some 40 years of usage, and currently as well.
Sounds like the mid to late '70's Bullseye powder issues. They traced it to overcharging cartridges, while using a progressive loading press.
A handful of shooters blew up their revolvers, and blamed the powder for erratic pressures, when it was actually errant loading practices at fault.
Matter of fact, Blue Dot always provided the most stable velocities and least flattened primers, which is generally due to a lower pressure.
I use single stage equipment, and my powder charges are physically examined 50 rounds at a time.
That is likely a major reason for my reloading success, I am very careful and capable.
H-110 and W-W 296 never had erratic pressure issues in hot weather, rather it was widely publicized by W-W in their reloading data back in the late 70's, not to use W-W 296 in temperatures below 36 degrees.
H-110 and W-W 296 are both the same exact powder, and manufactured by the only Ball Powder plant in the USA, and it is neither Hogdon Powder, nor Winchester who manufactures that ball powder.
At this point, I can no longer recommend that anyone use Alliant Blue Dot, but since I've never had issues with it, I'm not about to dispose of a few thousand hand loaded cartridges.
