Excellent. Now, when you do your H4350 with your 147's, go up past 41.5g and work up to 42 or 42.5 in .2g increments. Hornady brass has a larger internal volume than your incoming Lapua Brass....
For example when I used Hornady vs Prime/Norma brass: Prime was on average 10 grains heavier.
With your Lapua Brass... it's heavier and stronger than Hornady. You will need to lower your charge weight by 1 to 2 grains to have the same velocity as the Hornady.
Like @MakeSawdust said above. The Rabbit Hole is an insidious bastard that really sneaks up on you. Next thing you know, shit's all over the place and you need to narrow down what could be wrong from 20 different variables.
I use all Lee presses and dies, and have been doing so since I started reloading a decade ago. I'm no authority at all, but I refuse to get truly insane to try to get my groups to shrink from .5moa down to .4moa.
My 147 ELDm Thread was a great learning experience for me and my other Nosler 130 RDF thread I reference in there was a good experience as well.
Welcome to the world of one day it's, "MAN!! What awesome shooting I did today!!" To "what the fuck happened today?!?!?"
Yes, one thing I didn't stress is that I had a lot of trouble when I started experimenting with things. Most of the issues I've had reloading were because I left good behind in the pursuit of better. Sometimes I found better, and sometimes I just found a lot of frustration.