Handloading comes with some risk. And, handloading is part experimentation at times. Know what your personal comfort (risk) level is.
Among the many WARNINGS that the reloading books have published, is the load data. Data, that they have tested and considered to be SAFE loads. Most books will state what brand of powder and how much powder to use, primer, brass, and COAL.
But, what you may have on hand, may not exactly match with what the book used. And, what's the use of COAL given in a book.....IF, the ammo you made, won't feed through your firearm?
So, I will at times.........consider what the book said as a, "start or suggestion." I know that I could "tweak" the loads to a point.
But, consider your own, "pucker factor."
That's why the book also says to start 10% below maximum.
Aloha, Mark