GatCat pretty much nailed it.
The majority of the "cheap stuff" you find out there is High Velocity. It is typically between about 1,240-1,320fps.
For example:
Federal #510's as well as the #745 and #750 Bulk Packs
Remington Golden Bullets, Cyclone, etc.
CCI Blazer and Mini-Mags
American Eagle 38gr and 40gr loads
This ammunition should be safe to load in all firearms chambered for the .22
Long Rifle. It has been around for a VERY long time.
The majority of Semi-Auto rifles are manufactured assuming "standard" and "High Velocity" ammunition will be used primarily. Many manufacturers will recommend High Velocity rounds to assure proper cycling--as standard velocity may not always cycle properly.
Hyper Velocity did start with the CCI Stinger, though it is NOT the fastest stuff out there anymore.
Overall, the round is the same length as a standard 22 Long Rifle round. However, the bullet itself is shorter--this allows for the case to be slightly longer. A longer case means you can fit more powder, a lighter bullet means you'll get more velocity.
Hyper Velocity rounds pretty much include anything around 1,400fps and above...the CCI Stinger and Velocitor fit in this category as does the Aguila Super Maximum Hyper Velocity (Worlds fastest 22lr at over 1,700fps) and the Aguila Interceptor (Worlds fastest 40gr 22lr).
Almost all manufacturers will post a warning about using
HYPER velocity rounds in semi-auto firearms. They put a higher level of stress on all the parts, and cause cause damage or premature wear to buffers, slides, receivers, etc. I also would not recommend putting them in older "antique" rifles, even if chambered for .22 Long Rifle. It's unlikely damage would occur, but why risk it?
Also, as mentioned, the design of the bullet for most hyper velocity rounds is such that it has a tendency to firmly engage the rifling when chambered into "Match" grade chambers. Generally, it's not recommended to use them here. There is a high likelyhood of the bullet becoming lodged in the rifling when attempting to eject an unfired round. It can also damage rifling/chamber over time.
Here are a few excerpts from user manuals--I posted these in another thread recently.
If you have any concerns about using a certain ammo in your firearm ask the manufacturer(s) for their opinions. I shoot primarily High Velocity ammunition (and a LOT of it!) and haven't had any problems in any of my (several) semi-auto rifles and handguns.
Mossberg 702 Plinkster
Ruger 10/22
Ruger MKII and 22/45
Marlin/Glenfied Model 60
Marlin model 795