I agree the Handloader magazines are a valuable resource. I won’t argue the semantics of the two columns but if you look at Shooting Times from 1962 through 1967 or so you will see in Ken Waters Precision Handloading column, a Pet Loads column.
Ken Waters and Dave Wolfe have the shared experience of having written for Shooting Times.
The Pet Loads article “Developing Pet Loads” is a re-written and updated version of “How To Develop Good Handloads” from the August 1967 issue of Shooting Times.
Waters once wrote his first article was published in 1936 but I have been unable to find any of his early writing. By late 1962 Waters wrote he had written technical gun articles for ten different publications, I would like to know which ones - other than Gun Digest.
I believe some of the letters in his Ken Waters Notebook pre-date his writing for Handloader.
Ken Howell said that Waters was always a freelancer for him and the pay for his Pet Loads columns was quite low.