I have found that shooting light loads are sometimes a little dirtier and when I increase my loads by a couple of of grain I get less residue. For example, when I load 4.0 grain of HP-38 for my 38 special load my cylinder and barrel are dirtier than when I load the same powder at 4.4 grains.
Just a thought;
Mike
Later;
I said I increase a couple of grain but I meant to say a couple of tenths of a grain. That being .02 or .o4 not ?.0.
Later,latter;
Those darn decimals never go where I want them to, Tenths should be .2 or .4, I guess all those years in the 6th grade are not paying off.