My CZ 452 is easily my most accurate .22 bolt gun (out of a half dozen different ones), and I would expect the 512 to be in the same tradition, but I don't own one so I can't speak to it one way or the other.
I do own a 10/22 carbine, and... Well, accuracy wise, it sucks. Really, really, sucks.
I picked up a Marlin Papoose on a whim earlier this year, and guess what? Even it was more accurate than my 10/22.
Since I was having good luck with it, I decided to pick up a 795 to go alone with it. And it edged the accuracy up even a bit more.
A 512 would probably beat it, but a 512 will run over $500. For that money, you can get a Papoose, a 795, a Bsuhnell 3-9x scope and some rings. And a few boxes of shells to try everything out.
And I still want a 512, so I should probably stop talking about this now...