I did a similar test with 9mm loads last year. Without a doubt, Winchester Ranger Bonded 147gr had the lowest flash, followed by the Win Ranger Bonded 124gr+P. I asked a Win rep and they use much higher quality low flash powder than many of their competitors. Both standard pressure Speer Gold Dots and Federal HSTs had similar levels of flash, which I would classify as medium. Moderately distracting, but not too bad with standard pressure. The 124gr+P and 147gr+P were noticeably more flashy than their standard pressure counterparts, to the point of getting distracting.