I go to the experts that make the powder or bullet (or both), use their data for most accurate load and if it works for me then I am as happy as a dog with two d!cks.
I am not a sniper who gets to shoot of a steady rest each time, so for a deer stalking round I am trying to better what I can buy on the shelf, and I have been managing that for a while now (even with copper

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I have Norma brass at the mo, been using that for a while, then I have a load of PPU I will use. Only brass I found to be Sh!te is American stuff.
Was using Remington primers until I could not get them now have hunners of CCI.
Only issue that has come up recently is copper rounds being much shorter in AOL than the equivalent standard due to bullet shape. I went back asked the expert and problem was solved.
So seating depth is very, very important, especially if you don’t want a bullet stuck in the barrel when your cleaning rod is 100 miles down the road and cannot pop it back out.
You can get very anal about reloading but if you enjoy it and have resources then why not?
I did recently.
I can now shoot 130gn copper and 150gn (308) without changing my zero, how’s that for being anal? Took me a couple of visits to the target to sort that one out.
I do like a wee challenge as much as the next person.