I think it was the mention of CCI Blazer that first got me interested, because surprisingly enough...it's the cheapest HV ammo that my CZ 452 Varmint shoots best. (the one pictured is a 452 American 16" variant...which was never built with iron sights

) The trigger on that bolt gun has been reworked, and I did my load testing on a pretty steady bench with heavy bags. A pretty good heavy gun with a good trigger properly supported, and you'll get a good sense of the good/bad/otherwise. @ 50 yards, it's reliably under 3/4" in my gun, but important to point out that in that fairly controlled situation, I see the some fliers that I'm about 99% sure are ammo-related. I get fliers in the same set-up using CCI SV, but the groups are on average smaller, the fliers less common...and not as far away from the shots that printed well.
Having said all of that, I always test with every ammo type I have on hand at the time...and 3 things come from every session like that;
1. I learn which ammo is the worst
2. I learn which ammo is the best
3. I ignore #2, and pick the best-shooting ammo that is around $10/50 lol
I jest, but that's probably a pretty accurate description how it goes. A couple of years back, I got my first really snazzy 22.....and learned it shot SK Rifle Match really well. That was until I tried RWS R50. Looking at what both cost, the gun enjoys a fairly steady diet of SK Rifle Match.