When I started I listened to a bunch of traditional guys, Bore Butter, steaming hot water, Murphy's Oil Soap, Crisco, etc. I came to think it was normal to have a coat of rust in the barrel all the time and was to young to know better (and no internet to educate me differently).

Well, now that gun is no longer accurate. And I know that fat is for cooking or burning and not for gun barrels.

Clean with the appropriate solvent for your powder and protect with oil. No need to pump hot water through to speed the chemical reactions of corrosion. Haven't had a spot of rust since.