Bob- you're using WD40 for patch lube? That's interesting. I've never thought of doing that but know it's supposed to be fish oil based- however is not water soluble and therefore probably does a poor job of softening fouling- mayb e?
As can be seen, there are a lot of good and best patch lubes.
Dan has a point about the Castor Oil. Pressure does not effect it- it is the highest anti-pressure oil there is, it's burning temps, higher than needed to burn off synthetics that converts it to a varnish - yet that doesn't happen inside of an engine, only on the outside. The time factor might eliminate it from burning at all- afterall, the ball is out pretty quickly- but I'm wondering about the oil left inside the bore softening the fouling, is that slowly building as varnish?
Hoppe's #9 Plus has changed over the years - 30 & 40 years ago it was very viscous, milky substance. Today, it is darker and has kerosene in it- but it's still water soluble, or rather will mix with water. It is a good target lube - maybe not for hunting in damp areas. Taylor's test up here showed no rust for a week's loading- fresh, clean bore. It didn't wet the powder, either - yet 54Bucks got a rust ring - in Pa. When Taylor did the test, the humidity would have been between 20 and 40 - probably, but he brought the pistol barrel inside every night so the condensation would damp everything. The barrel had spots on the outside, but not inside. Knowing Taylor, that patch was sopping wet with the "Hoppe's Plus" when loaded. I don't know if it was new or old Hoppe's that Taylor used = new, I think.
