Nice pix, nice groups, Crusty!
You told us about the ammo and groups, how about the scopes?
I've got a 10 year old or so 452-2E ZKM, not sure what that all adds up to, wears a 3-12X40 cheap Tasco with adjustable objective, a rimfire benefit which I can't see on your rifles. Helps me with parallax, but takes time setting up the shot and the calibration on the scope never coincides with my eye.
I plink from a bench at 25 and 50 yards at soft ball size Wiffle balls anchored with screws to the dirt backstops with Remington Golden Bullets from 525 round packs. I suspect that combination gives tighter groups than your Varmint. Not because my cheap ammo or old rifle are any better, and fer sure am not likely to be a better shot, but because if you don't have your scopes adjusted for parallax, they can't shoot as well as they might. Most fixed parallax .22 scopes are set for 50 yards. Most fixed parallax centerfire scopes are set for 100 yards, the exception being shotgun scopes (usually 50 yards).
Oh, here's the write-up on my rifle: http://www.czub.cz/en/news/written-about-us/559-rimfire-rifle-cz-452-2e-zkm.aspx
My rifle doesn't have anywhere NEAR the sexy stock worn by the CZ in the factory picture. Looks like any medium weight target US .22, Winchester, Remington, Mossberg, Stevens...
Lemme know about the scopes. I've been thinking that a bigger 24X will be needed to really see what my rifle can do, just haven't gotten around to changing the glass.