I don't have a CZ 452 but my son does. I don't recall whether the ejector moves down, or not. I know it does on his Kimber, so using a bore guide keeps it out of the way of the cleaning rod. He also has a bore guide for the 452, but I don't know how it works with the ejector. In any event I'd recommend using a bore guide with any .22 for which one is available.

Stupidity has its way, while its cousin, evil, runs rampant.