I have never reloaded. I am currently having a rifle custom built. So I figure it is time to learn how to hand load my own ammo. I have read a lot of stuff on this site that has given me a good idea about how to start out. I have also read a couple reloading manuals. But the one thing that I don't quite understand, and maybe I have missed it, is when seating a bullet how can you tell how far off the lands you are? Is this based on knowing your chamber depth or is this something that you can measure? Sorry if this is a dumb question. But like the title says I am very new to the reloading game.