I don't shoot groups for proof of accuracy.
Groups lie to me.
Makes me look like I am doing better than I am.
Groups wander relative to point of aim.
Actual target aggregate group size is 2 or 3 times average group size.
For that reason, shooting for score is my method of conparing accuracy.
For that reason, I reiterate:
No rifle can fix poorly made ammunition.
No ammunition can fix a poorly made rifle.
No two cartridges are identical as they roll off the assembly line.
Cartridge quality/uniformity determines results.
Try shooting for score with your rifle's "preferred" ammunition.
Not groups. What happens when punching center?
Inexpensive cartridges can't get the job done.
Too much velocity variation, too many strays.
Try it, 50 yards, for score. Compare results.
This. I shoot a relatively modest CZ 457, with a Lilja barrel and a wood stock that has been modified to fit my needs. Its ugly, but it works. I headspaced the barrel at .043 specifically to run SK ammo, because that's what it likes. Generally speaking, it shoots about the same with SK Standard Plus as it does with Long Range Match, the difference being in the consistency.
The range where I shoot offers a rimfire target card that is based on an ARA card. Same size targets with the same scoring scheme, the difference being that these cards have 40 targets on them and a perfect score is 4000, intended to shot at 50 yards. With a good lot of ammo, I very regularly shoot 3800 or better, with perfect scores not being unusual.
Lots of guys swear by their low cost ammo, usually CCI SV, touting the groups they've shot, but I have never seen anyone shoot better than a 3200 or so with any type of CCI ammo.
If you really want to know how your rifle, shooter and ammo combo does, score it.
I'm sorry, but rimfire is a sore spot for me. There was a time in my life when I lived for precision rimfire and I have a good idea of what it takes to have a truly MOA or better setup and the misinformation that is spread around makes me crazy.
If you're shooting a bone stock anything based on a 10/22 action, I'd say get a case of Federal Automatch and just go have fun. You'll be thrilled when chance delivers that 1" 100 yard group.
As far as Ive seen, CCI doesn't make match ammo.