Agreed about Winfer's books; I bought a couple when they were new and relatively inexpensive and am filling in the gaps with used copies. But even with the huge availability of "used books cheap" in the metro LA area (one of the GOOD things about living here!), they are hard to find and usually not especially cheap. But the hunt is fun....
I enjoy Campbell's two Win SS volumes and especially Roberts and Waters' "Breech-Loading Single-shot Rifle" although I have only a cheapo paperback of that. I like Frank Waters' "Pet Loads" too. And I have to admit to liking Frank de Haas' "Mr. Single Shot" books, although I suspect that they have led to the "Bubbulization" of more than one fine rifle.....(I should probably have only mentioned them under "Misfires"!).