With match grade .22 rf ammo, as others have said, you pays for what you gets.
You can find some less expensive ammo that will give you some impressive 3 or 5 shot groups. Then when you go on to several 5 shot groups, you find that you get what is charitably called "fliers". That's a round that gives you the unexpected 9 or worse, an 8. Variations in priming mix, powder charge, bullet weight, bullet lubrication, bullet shape, bullet crimp, brass thickness, and on and on. The more expensive stuff will have fewer of these problems.
Yes, SK standard plus shoots well in my Anschutz rifle. BUT I get the occasional 9 and (rarely) a dreaded 8 in practice.
In serious rimfire competition, dropping an X, much less a 9 will lose you a match.
There is a reason that folks use high end, expensive rimfire ammo. Believe me, sir, if I could shoot consistent 200 / 15+ X targets with cheap ammo, I would. I cannot, nor can my fellow competitors. (I sure wish that they would buy cheap ammo, it would make my life easier
I'm sure that there will be several folks come on this forum and claim that they consistently shoot little tiny groups at 50 & 100 yds with inexpensive ammo & rifles. Unfortunately, they never show up a Perry or any other match.