If you could modify a 10/22 rotary so it could only hold one round it would be a single shot. Change back later on. Just a thought.
I like all of the guns people mentioned, but I remember when I was a kid and that influenced me with my kids. While in early high school the Remington 66 came out.
Forgive me for not knowing the model # but if I had to buy another .22 it would be one of those marlin's with the tubular magazine. Reason being is that I could then cycle shorts out of it. Would be handy for keeping rabbits out of my garden in my very small town. I think the sub sonic shorts are similar or even more quite then the crack of an air rifle.
How about just loading one round at a time?