Alliant's 2004 Powder manual had 38 special and 38 special +P loads listed using Blue Dot but I have no experience with Blue Dot.
I do have a pdf copy if that would help.
Blue Dot is excellent in 357 loads. I have used it in full power 44 mag 38 super and 357 loads. It is a slow burning powder that is great for the magnum cases. It has a nice flame front as well. For low pressure 38 standard or +p loads there are much better powders especially for short barrels. Bullseye is my current choice for 38 special loads.
I used blue dot to load high performance 9mm loads back in the 70's and early 80's..... Col. Charles Askins printed the load in his book " On pistols & revolvers". It was a "compression" load in the 9mm case, meaning that I had to load a portion of the powder....compress it...then load the rest of the charge on top of it and then seat the bullet..."crunching" the powder as it seated. It ran a 100 gr JHP out of a Smith 59 at an eye popping velocity over my chrono screens. It burned clean and was consistent on shot string velocities.