Launching012 - your rifle will tell you how much powder to use, by starting low, say 60gr.3F and shooting on target off a rest. I'd set the target no closer than 40 yards once the sights are roughed in, then increase the powder charge every 5 shots by 5 grs. Stop (and re-test with that load) when you have a group that represents the best your rifle will shoot.
Most rifles differ in what shoots best in them, just as many shooters have a different idea as to what is acceptable accuracy. One may demand 1" groups (on centres) or tighter at 50 yards, while to another, 2" or even 3" is just fine.
Most any load of powder will group 5 shots around 1" or better at 25 yards off a rest, but fail terribly at longer ranges. Many of us test loads at 50 yards minimum. If the rifle is zero'd at 25 yards, it is pretty much zeroed at 50 to 60 yards.
Many people use 3F up to .58 calibre, while many others use 2F. I prefer to have an accuracy load with both powders so whichever is available, I can still shoot accurately. Most guys here use 2F in .50 cal, while I have accuracy loads with both granulation's in my .40 and .45 as well as the larger calibres. Generally, 2F requires 10 to 15gr. more powder to equal the accuracy and speed of 3F.
For example, my .45 needs 70gr. 3F to shoot accurately at 50 yards and beyond, but requires 80gr. 2F to match that accuracy. In the .40, it's 65gr. of 3F and 75gr. of 2F.
Whether you want to wipe the bore between shots, or demand the ability to shoot multiple shots, 20 or even many more without having to wipe, will also make a difference in the load requirements as to patch thickness and ball diameter.
We normally shoot balls that are .005" under bore size, with a denim patch that is .020" to .022" thick. Loading is quite easy (using a short starter) and we shoot all day without having to wipe the bore - the fouling NEVER builds up in the bore, no matter what the weather.