The Lyman are the best, they have been in the business for about 125+ years or more. They produce ONLY casting and reloading equipment, therefore they try and record data on all brands of cases, bullets, primers and powders. Their books have extensive articles also on casting, powders, bullet alloys, ballistics, and equipment. They usually have 8-10 powders for each bullet weight, they list chamber pressure, velocity , the whole 9 yards. Many load books tell you min/max loads (what) , this tells you how, why, when and where.