Blue Dot powder has always intrigued me. From the time of its initial introduction in the mid-1970s, it has been something of an outlier. It was a bit too slow for my usual high-order pheasant and teal 2-3/4" 12 gauge loads (3-3/4 dram equiv. x 1-1/4 oz lead shot); Herco did and does great work in that realm. I didn't and don't load 3" or 3.5" 12 gauge shells. Herco also does good work in 20 and 28 gauge, while 2400 is a natural for 410 x 3" shells.
I remember an article by Bob Milek in one of the gunrags c. 1975 about the then-new Blue Dot in 357 Magnum. He liked the powder in the 357, but remarked that in temperatures below -35* its behaved with spikey pressures in an unpredictable/random manner. Not a huge question for much of Kalifornistan, but it still rattles around in my head a bit. In later years, Alliant pulled all of their data in the 41 Magnum using Blue Dot powder, and added cautions about using it in 357 Magnum/light bullet loads. SOMETHING causes these anomalies.
Blue Dot gets its usage in 10mm at my house. I don't load "Norma level" loads (200 grainers at 1200 FPS), but I do run my Glocks at the Win Silvertip ZIP Code--175 to 180 grain bullets in the 1225-1250 FPS bracket. These are FUN in the Glock 20, and a bit of a handful in the Glock 29. You want "Flash bloom"? OY VEY--light off some Blue Dot in that G-29 at dusk in a desert box canyon. YEE HAW--the kids call them "Dad's Dragon Breath Loads". They don't want to shoot them, but love watching me do so. Yes--they would not be the best thing to have on board in an exchange of finality. There would be tough questions about the singed eyebrows on your assailant.