The average tree in your woods might be a 100, the areas i hunt are about 30-40ft, 20yard shot is typical, does anyone make a subsonic for a 22mag? Seems kinda contradiction if they did but i would buy it, i already use aguila sss in my 10/22
Folks tend to think where they hunt is the only habitat on the planet.
I've hunted east Texas a lot where the pines are tall, but I grew up in live oak where the oaks spread out and don't grow so tall. They give squirrels highways to run, the limbs being horizontal. These live oaks range from 20 to 40 feet or more, but no where near as tall as those east Texas pines and, of course, not as straight. You won't find yourself in a climbing tree stand in a live oak, LOL.
I grew up hunting in the oaks and .22 CB short was a real squirrel getter. Up in those pines, shots can run 50 yards and the LR was much better. ,22 mag is overkill and the ammo a might more expensive, so I've never used mine for squirrel, but it ain't like it can't be done or even that it's a bad choice. I just like to be a little more quiet.
I know of no subsonic .22 mag, but Winchester Dynapoint is pretty weak compared to CCI maximag. I have my reloading/chronographing notes boxed up in storage waiting to move, I hope soon, so I don't have the numbers handy, but the ammo is so weak it sometimes doesn't work the action in my semi auto Remington 597 magnum. It chronographs significantly weaker than CCI maximag, but it's still a bit hotter than most any hyper-velocity .22LR and is pushing a full 40 grain bullet. In a bolt gun and in sold point, this might be the ammo of choice for squirrel if it's accurate in your gun. I had no complaints with the stuff for accuracy.