Load Data
Gavin from Ultimate Reloader, in combination with Frankford Arsenal, discusses the science of finding the load data for the cartridge you're reloading.
Where Should I Begin?
When starting this journey it is best to get several reloading manuals, preferably hard copy, so you can quickly and easily cross-compare the load data of different manuals for your specific cartridge. Once you get an idea of how you want to load your cartridge, you'll want to invest in bullets, cases, powder, and primers.
When it comes time to start pouring powder, it's important to always start near the minimum powder charge weight, and progressively work your way up. This will ensure chamber pressures start low and keep you and your firearm safe from mishaps. Taking detailed notes during this process is always beneficial in making sure you are loading the right cartridge to the right specifications giving you the confidence you need to be able to reload ultra consistently from batch to batch.