I had expert teachers - Dean Grenell, Skeeter Skelton, Elmer Keith, Jack O'Connor, etc. I learned how to reload by reading, something that a lot of folks don't seem to know how to do these days - or choose not to, at any rate. This was in the B.C. days - before computers.
Of course, I still had to experience my personal learning curve, but reading magazine articles and books gave me a very good start.