Since Newtown I think only .22 ammo readily available has been low powered stuff
High velocity disappeared quick off shelves
I have seen general “high velocity” and “standard velocity” .22 LR ammo.
The ultra high velocity stuff, like Stingers and Velocitor ammo has been pretty hard to find, but I did not notice it was harder than other specialty ammo.
On the other hand, the whole world has been trying to fill the demand here in the U.S., and a lot of that effort has been “match” ammo, which is usually sub-sonic, so it has a bit less energy than the high velocity stuff. If you include the foreign suppliers, there may well have been more ‘low power” .22 on the shelves.