Does no one else consider Brian Pearce to be a very good writer with oodles of field experience? I respect him considerably. He appears in, "Handloader" and in, "Rifle."
And a pretty good case could be made for Sheriff Jim Wilson as a sort of latter-day Skeeter.
Col. Rex Appplegate didn't write much in gun magazines, but his book, "Kill or Get Killed" is a classic. This guy was the primary trainer for OSS agents, later CIA.
I only met Applegate once. Had lunch with him and a couple of other guys at a Ruger function for the press during a NRA convention. It was Ruger's 30th Anniversary, and they put on a pretty good feed for the gun media. Rex was modest, and amused when I told him that I had my dad's 1944 edition of his book. He laughed and said, "Well, I was certainly thinner in the photos then."
I never met Jack O'Connor, but corresponded for years. He was a bit of an elitist, like Cooper, but if you wrote to him on decent stationery and could spell, he was nicer than I've heard he could be to those whom he considered to be unwashed rednecks. I used to write for an editor who knew Jack in person, and he said that Jack was a little uppity and gruff. I know he was in a college fraternity, so that doesn't surprise me, given my limited experience with frat rats. He was also a college professor, which accounts for some of his attitude, I think. But his wisdom, not limited to the .270, was impressive. He wasn't too heavily into handguns, and didn't know much about Bianchi and Safariland when I asked. Referred me to Lawrence, with whose products he was comfortable. Jack had a droll, witty style that I liked a lot. He died in 1978, I believe, on an ocean cruise with his beloved wife, who was often featured in his hunts.
No one has mentioned John Wootters. That's spelled like I did it, although I've seen numerous misspellings of his last name. I don't know if he was really a gun writer or more of a hunting writer. He certainly did write about guns, though, and Bill Jordan once told me that John was a true wordsmith, whereas he, Bill, was just a shooter who wrote. Jordan was being excessively modest, but Wootters was as skilled with the written word as he was with a camera, and he was a superb photographer, of animals as well as of guns and terrain. I believe he's still living, but he retired about the time that Bob Petersen died. (Wootters wrote mainly for Petersen's in his later career.)
John's books, especially, "Hunting Trophy Whitetails" are well worth seeking out.