The .45 acp is pretty low pressure and low performance, so it does not take much of a lubricant to prevent Leading.
Too small a bullet can cause Leading. I like pistol bullets to be at least .001" larger than groove diameter.
Too soft a bullet, especially in a rough barrel or where the lubricant isn't very good, can cause Leading. A lot of .45 acp shooters like soft bullets for it, believing that they will upset on firing and seal better: I'm not one of those people, I like them hard.
I find a BoreSnake takes care of any Lead wash in the bore of my Colt Series 80.
When you start with 9mm or .40 S&W, everything will change because they're much higher pressure, and because 9mm barrels usually have oversize groove diameters.