Did you upgrade your barrel?
There is only so much accuracy you can get out of a 10-22. The 10-22 is sold everywhere and in incredible numbers. So that Ruger does not have to deal with complaints that a gun is not functioning, they cut the sloppiest chamber on Earth. The result is that 10-22s feed virtually any ammo but the tradeoff is reduced accuracy. It is a great plinker.
An individual 10-22 will shoot some ammo more accurately than others, but if you don't address the barrel and it's chamber limitations, you will probably never be happy with it as a squirrel rifle.
This is life. There are no perfect answers. Only tradeoffs.
Some observations...and things I've read...
The 10/22 is a great plinker...and it's the small block Chevy of the rimfire world.... anything is available for it....and the rabbit hole is DEEP!!
I've owned about dozen CZ 452s, 455s, and 457s...never owned one that wouldn't out shoot any 10/22 (or any other 22) I've owned.
Can a 10/22 be made to shoot? Yes, I'm sure they can. I just haven't found the trick yet. Pretty sure the trick is to replace everything but the sling with aftermarket parts. Receiver, bolt, trigger, barrel, and stock. I've already got considerably more in this one than the most expensive 457 would have cost. Anymore and I'll be getting into Annie territory.
I have done a mock up with a shim under the front receiver pad thing...to see how "free floating" the barrel would effect things. I didn't shoot it because it was obvious that it wouldn't work. With only one action screw, it turns the barreled action into a teeter totter. Unless you buy a new receiver with a rear flange, there is nothing to hold the rear down. Guess that's why most 10/22s have a barrel band. Additionally, if you do free float it...now you're dealing with a steel barrel in a thin aluminum receiver with nothing supporting it. In the 10/22 world they call what will eventually happen....barrel droop. This is a rifle I intend to hunt with, not a bench rifle that will spend a fair amount of its life in a hard case or gently sitting on a bench. I'm sure it would be picked up but the forearm/barrel end. That, I'm sure, would put even more pressure on that "unsupported" barrel/receiver junction. So...what to do?
For now, I'm just going to leave it the way it is. I have replaced the factory barrel with a 16.5" GM SS fluted factory contour"match" barrel...it has the "Bentz" chamber. I've also replaced the trigger group with a Timney Calvin Elite 2-stage trigger (it's sweet, BTW).
Short of replacing the bolt/receiver...not much else I can do. I'm trying different ammo now. The tenex EPS has shot the best so far. I'm waiting on an order of "subsonic hollow" to get here. I've had issues in the past with RN target ammo ricocheting through the woods (I hear it bouncing off limbs). I would like to avoid that if possible. If the SH shoots good, I'll stock up on it and call it good. If not..I'll try the Aguila or CCI subsonic HPs.
Which brings me to another issue....mini-mags. This is a 16.5" barrel. Had I went with the 20", I would try the MMs. I've read that the 22 will get all it's going to get at about 16"... anymore and the barrel is actually slowing the bullet. I've even read that some of the better barrel mfgs will make the last few inches a slightly smaller ID...to intentionally slow the bullet. Something about bullets leaving the barrel supersonic, and going transonic between muzzle and target and upsetting the bullet. It's more than my tiny brain can fully understand...but the idea makes sense. So...all supersonic ammo is out!!
Wow...this post turned out longer than I intended...lol
I love the idea of using a 10/22 for squirrel hunting, but if accuracy is your end goal, save yourself some $$, and just buy the CZ. It will end up costing less...and will out shoot a 10/22 all day long. Yes, I'm aware there are exceptions...but I'm speaking generally.
