Don't worry about it.
I have used W231, Unique, 2400, AA#5, Blue Dot (a terrible choice) in the 45 LC. I have also used Bullseye but it has been a long time.
I shot some titegroup, my recollection was that it too left residue.
Anyway all of these powders leave unburnt residue. While I have not used every powder on the market, of the ones I have used, they all leave unburnt or partially burnt residue.
I dump my cases direct from the cylinder into a plastic container. When I scoop them out, there is always a quarter teaspoon, maybe more, of powder residue that fell out of the cases and on the bottom of the can.
What is of more importance are the velocity SD and ES's. When you have a powder, like Blue Dot, that leave Extreme Spreads in terms of hundreds of feet per second, then the powder is not appropriate for the cartridge.
Like Blue Dot in the 45LC
5 1/2" USFA Rodeo
250 LRN (.452") 11.5 grs Blue Dot R-P cases, WLP
11-Sep-05 T = 85 °F
Ave Vel = 845
Std Dev = 48
ES = 183.6
High = 933.3
Low = 749.7
N = 18
