Blue Dot is not my favorite powder, but I buy it for a finicky 10mm 1911 I have. I wanted to find another use for it so that I could use it up before it rotted. Thus my nervous work up of a load, with no published data, for the .500. I see now others have done the same.
I see many loads in the books for .44 mag using blue dot.
I think the main down side is that it seems to be dirtier than other powders I use, and it is position sensitive.
Leaving the .500 for the weekend and shooting the .204. Ain't Handis fun!
mike