Update!
Had a chance to test 8 different powders the other night and I wanted to share the results with you. Some were surprising.
Bullets were both 230 grains and ignited with WLP primers.
Longshot, 6.4 gr, Win FMJ, HUGE (of course) flash
Bullseye, 4.7 gr, Win FMJ, Large (surpise) flash
Bullseye, 5.3 gr, Speer Gold Dot, Large flash
AA #5, 7.9 gr, Win FMJ, Large flash
AA #5, 7.9 gr, Gold Dot, Large flash (but smaller than FMJ)
Unique, 6.1 gr, Gold Dot, Large flash
700x, 4.9 gr, Win FMJ, Medium flash
700x, 4.9 gr, Gold Dot, Medium flash
Green Dot, 5.3 gr, Win FMJ, Small flash
Green Dot, 5.5 gr, Gold Dot, Smaller flash
Nitro 100, 4.9 gr, Win FMJ, Small flash
Nitro 100, 4.5 gr, Gold Dot, Small flash
Herco, 6 gr, Win FMJ, Small flash (surprise to me)
Herco, 6 gr, Gold Dot, Small flash
Solo 1000, 5.4 gr, Gold Dot, SMALLEST flash
with what I've read, my impression was the faster powders, like Bullseye, would have the least amount of flash and the slower/est powders would have more. Glad I tested this theory. It didn't always hold true.
Bullseye was a shocker. It's usually with the first 3-5 fastest powders, depending upon which burn rate chart you look at, at yet it's flash was almost comparable with the Longshots. I knew the Longshots muzzle flash would be huge. I used it as a base line. Was dissapointed to say the least, I had hoped it would burn quickly enough to offer a small flash. BE offers the velocity and accuray I wanted. Guess it will stay a good daytime powder.
Herco was quite a surprise as it is quite a slow burner and yet offered a small ball of fire.
Solo 1000 will become my self defense powder, as it gives me the speed, accuracy and now, the smallest muzzle flash of the powders I tested.
Big Al