Forgive me, but I just gotta; No Offence to the OP intended.
Lately, "cleanest burning" seems to be the new "buzz word/phrase"
barf
, I see this question on every form I follow.
All powders will leave some soot or burned granuals, some more than others, but nothing like black powder! I have never, in 27+ years of reloading had a handgun fail to function because of "dirty" powder (the most I've shot in one session was 250-275 rounds of 45 ACP through a 1911 and mebbe 300 rounds in a 38, 95% cast lead, and I clean my guns after each session. Most times I use multiple guns). I've read of shooters not liking dirty hands from shooting, but that's why I use soap and water after shooting, and keep a hand towel in my shooting bag just for gun/hand wiping, and it's never, never a problem with my note taking/writing down my results. I also take water with me when I shoot outdoors and wash my hands and face when I'm done shooting (but I don't look like a coal miner after a 10 hr. shift!). I don't, and I don't know anyone that wears a white tux to go shooting, except James Bond, and everyone that shoots will get some GSR on them, it's just a part of shooting a handgun. In my entire shooting "life" I had
one problem with "dirty" powder; that was with an 1851 Colt Navy copy and the cylinder would bind after 12 shots.
I chose powder for my reloads by it's performance, and sometimes by availability.
When I'm done shooting, nobody, except a CSI agent, can tell I've been shooting, except for that silly smile on my face...
Sorry if I offend anyone, jes my old guy way of thinkin'