Critch, A couple of sources I have in my library are, "THE NRA GUNSMITHING GUIDE-UPDATED" and "BOLT ACTION RIFLES" Expanded 4th Edition. The NRA book has quite a few barrel thread specifications and both of these books can usually be had used on Amazon.com. I know some of my other Gunsmithing books also have some of that info but can't remember off hand which one's. The NRA book is a good one!.......................Dick P.S. Got to looking at some other books and there is also some barrel thread info in Harold Macfarland's "Introduction To Modern Gunsmithing".