I can't locate my copy of Angiers "Firearm Blueing and Browning" but I recall different recipies for solutions being described as having more or less "bite". The formulas I have used call for dilution with distilled H2O and increasing the amount does lessen the agressiveness. Shorter rusting times and lower humidity also help. A finer polish is a waste if your solution is agressive, but will help with a formula that produces extremely fine grained rust. The latter seem to take more applications to get a deep blue, at least with the formulas I've tried. My very first attempt for practice was on an H&R 922 revolver that I hand polished as fine as any pre-war Colt. My home brewed solution made it look bead blasted. Live and learn.
