There are published loads for all calibers and bullets. These are loads developed by the powder and bullet manufacturers using state of the art equipment. Stay with those loads, live long, and prosper.
I would suggest picking up a couple of reloading manuals. They contain a ton of great information regarding everything you have inquired about.
My dad was an aspiring chef when he joined the army. He was supposed to be a wheeled vehicle mechanic. It became known that he could run a kitchen and his army career took another turn.
After being there some time he was pretty disgusted by the manners of the good folks he was feeding. He made a joke that he could bake a cake and just smash whole eggs into it, shells and all, and they would still shovel it down like pigs.
He was right. Lol.