The stock has a shelve at the rear that accepts the trigger group/reciever in such a way to prevent this.
From Rimfirecentral
MKnarr "The question about "free floating" the barrel comes up quite often with reference to the 10/22. Part of it is caused by impricise answers. Let me tell you my thoughts on "free floating".
Every stock 10/22 I have seen, has a little pad of wood at the tip of the forearm under the barrel. That pad is not caused by sloppy workmanship by Ruger and they aren't that dumb to put it there by accident. It is there to support the receiver, not the barrel.
Try this experiment. Take your barreled action out of the stock and lay it on the table. Put a pencil under the barrel and move it back and forth until the barreled action is balanced. Well almost balanced. How far in front of the action screw is the pencil? What you now have is a teeter toter. When the barreled action is screwed into the stock with the single takedown screw, the rifle still wants to teeter about that same balance point doesn't it. That's why many guys that buy an after market stock, sand out the barrel channel for their new .920 barrel can push the barrel down in the stock. Actually the receiver is coming up in the air.
So the recommendation when bedding a 10/22 is to bed the rear of the receiver, the front if your aren't using a pillar which is actually the best way, and the barrel channel out to at least the balance point and a bit beyond. Now when you tighten the single takedown screw, it will trap the barreled action between the rear of the reciever and the bedding under the barrel. This is what most people are refering to when they say a free floating barrel. On actions with multiple screws, you can actually free float the entire barrel because the reciever is trapped by the multiple screws.
Anyone who floats the entire barrel on a 10/22 with a single screw and gets half decent groups, is just plain lucky. More than likely, the groups would improve with bedding under a portion of the barrel. And the bedding under the barrel is not there to support a barrel and keep it from drooping, it is there to support the receiver. Unless your barrel falls into your receiver, you aren't likely to get much barrel droop if any."
http://www.rimfirecentral.com/forums/showthread.php?t=151601&highlight=teeter+totter
Vincent "Thats why you are supposed to glass bed the 2 or 3 inches at the chamber end. If you had done that you would not be getting the droop. I also shim under that area with cut targets if I'm not ready to bed.
I keep writing this. Bill ruger designed the 10/22 to have the barrel band and if not that AT LEAST a forearm tip pressure pad. On my 1976 carbine the pad is much more noticeable that new ones. When you take this away not only will the barrel droop but you are stressing that flimsy aluminum action and you are going to have other problems.
If this rifle were mine I would shim the forearm tip to get the barrel BACK to where it is supposed to be and then bed 2 or 3 inches in front of the chamber. Do that and you need no special rings and no adjustable vee block. The barrel needs support. The other methods only bandaid a bad problem you have created. I even bed 700 Remingtions like this and they have TWO anchor points and a massive steel action. The poor little Ruger has ONE anchor point assuming the barrel band is removed or floated and that flimsy action.
What you are doing right now is stressing the heck out of the action screw area. I would not even be surprised if the the action is up in the back as it has teeter tottered up when the barrel went down.
YOU DO NOT WANT TO COMPLETELY FLOAT A BARREL UNLESS YOU DO OTHER THINGS LIKE ADDING A SECOND ACTION SCREW. The rifle will be more accurate besides. Shim it for now and bed it soon. "
http://www.rimfirecentral.com/forums/showthread.php?t=159187&highlight=teeter+totter