Finn Aagard, Charles Askins, Massad Ayoob, Craig Boddington, Jim Carmichel, Lucian Cary, E. C. Crossman, Bill Jordan, Elmer Keith, Jan Libourel, Jack O'Connor, Warren Page, Alexander Rose, Skeeter Skelton, Mike Venturino, Townsend Whelen, Jim Wilson....
Not to take anything away from Sam Fadala or John Taffin, it's just that I've read less of their work.
Theodore Roosevelt is worth reading also.
A dog ate my copy of Crossman's Book of the Springfield, and I gave away Whelen's Days of the Krag and Days of the Springfield. I met Co.l Whelen once when I was 14, and he let me shoot a Winchester Lo-Wall in .22 K-Hornet. Looked up to him from that day forward. I've also been a single shot .22 centerfire fan ever since.