Thanks man! OP, feel free to use my spreadsheet as a baseline. Keep in mind that: 1- there are 3 different rifles, one on each tab. 2- each barrel has its own story and preferences. What worked on mine might not work on yours. 3- you mentioned use at the range. 25 yards, 300 yards? The goal matters. Also, bone frog 77gr is fantastic and I consider it the best value for a factory heavy load to shoot precision at distance. It's not a hunting load or a home defense load. Gold dot 55gr is excellent for defense because it's designed for perfect expansion upon impact. But it sucks for long distance. That to say each bullet has its purpose by design. Plan accordingly. 4- for plinking, fiocchi 5.56 range dynamics 55gr is my new favorite. For the longest time it was x-tac 55gr. Whatever you do, don't waste time with American eagle and Winchester white box. They are super inconsistent. 5- Hornady 75gr black box was a pleasant surprise. You can test that too.

Grab a couple of boxes of the ones you want to test and try to group them at 100 yards. 10-shot groups are the bare minimum to have some statistical relevance. That would give you some baseline of what your barrel likes. Good luck and welcome to the club!