It is always wise to reduce loads a bit and work up to the powder charge you expect to use. So if your goal is to shoot around 64 grains of powder, build a couple of loads of 61, 62, and 63 grains to make sure that there is nothing that is going to cause excessive pressure. There are variables in terms how the chamber is cut, and the loading components, and working up is therefore always advisable. Even if you have experience with a particular rifle, changing something as minor as the manufacturing lot of powder can make it wise to work up again.
