Biggs300 brings up an excellent point. Whatever bullet/bullets you intend on loading up, you should use the same manufacturers manual. Bullets have different shapes between manufacturers which create different pressures and pressure spikes. You will end up having better results using the corresponding manuals. You can get away with using say a Speer manual for a Hornady bullet, providing they are the same in weight and base design, but you will honestly have better results using the manual for that bullet.