I enjoyed your post. A friend & I did the same thing over 2+ year span. We shot weekly, 12 months a year in all types of weather. We truly shot 1000's of rounds through revolvers, semi-auto pistols, several single-shot & semi-auto rifles with removable magazines & tube feeds
as well as longer barrels & shorter barrels. We used about every type of ammo available locally, (so "No, we did not use every manufacturer's offerings"). If your "go to" ammo didn't come in first it may simply be that it never got tested. (This testing was quite awhile back when ammo availability was much tighter than now) We did use various weights & HP's as well as RN. We each judged upon accuracy, reliability, & how well each fed, (where applicable). As Teri Anne pointed out ammo CAN vary from lot - lot# & certsinly what one gun loves another another may absolutely hate, (either in accuracy &/or basic operation). Weather of course plays in & dirt can affect not only accuracy but basic gun operation as well. In our unbiased independent tests it was our personal opinions & consensus that OVERALL, of those we tested: The Remington Golden Bullet 40 grain round nose was our favorite with Federal's 40 grain round nose "Blue Box" (Champion) a VERY CLOSE second. Our third choice was the Remington Thunderbolt. We thought that Winchester ammo seemed slightly hotter than others & shot very well at long distance. We got varying results with Aguila ammo. It was very reliable.
We encountered several rounds in those two years that would not fire (even in another weapon) but seemingly fewer of those in Aguila than the others with Winchester a very close second.
In OUR tests we did not find 'the perfect ammo that was all things to each of us' but we thought the 40 grain Golden Bullet came close.
In all fairness: At that time many brands/weights of ammo were not available to us AND admittedly Aguila likely didn't quite get a fair shake due to their wide diversity of ammos which we could not procure.
Actual results may vary of course. Your firearm, ammo, weather, gun care habits & abilities may yield different results. It was quite expensive & very time consuming but lots of fun!
Good luck with your testing. I am very anxious to see your results after you've finished. Enjoy!