I start at 5 % below book maximum and work up in 1/2 grain increments. When a load starts to show promise I then work with 1/10 th grain increments. Some of my toys are loaded well above what book max says. Reason being, every firearm is an individual. What works in one will not necessarily work in another. A safe load in one can cause death in another. Others are loaded 4 or 5 grains below what book says. Reason being short throat, tight chamber, match chamber or tight bore. Enjoy your reloading, but don't take chances as there is no forgiveness if you go too hot.