My favorite 22lr pistol is my Kadet unit on my custom cz sp-01. I may even have a rail for it, I like letting new shooters use a red dot sight. Extremely accurate and reliable and good training.

I have an airsoft p226 x5 open. It is a blowback pistol with an identical operation as the sp01. Without the rail (which I want to try on the kadet), compensator, and mag funnel the weight and size are really close. The mags can hold the same # of rounds as the 9mm and since the co2 is in the magi I can also practice mag changes. I just need to clean out the garage and have the 2yr old away for an afternoon to try it out.