the bullet remains stable in flight. Two performance classes of .22 rimfire subsonic rounds exist. Some subsonic rounds, such as various .22 short and .22 long "CB" rounds, give about velocity with a bullet providing relatively low impact energy (41 J at muzzle). These may not use any, or only small amounts of gunpowder, and have the characteristics of rounds intended only for indoor training or target practice rather than hunting. Where these are in .22 LR form, it is only to aid feeding in firearms designed for the cartridge, rather than older .22 CB shooting gallery rifles. The Aguila SSS gives about velocity with a 60-gr bullet offering energy (163 Joules) equivalent to many high velocity .22 long rifle rounds using standard 40-gr bullets. Other heavy-bullet subsonic rounds give similar performance, and are intended for hunting of small game, or control of dangerous animals, while avoiding excessive noise. Standard velocity The velocity of standard-velocity .22 LR rounds varies between manufacturers. Some standard velocity ammo may be slightly supersonic-around , other ammo such as CCI Standard Velocity .22 LR ammunition is rated at . Most standard velocity ammo has a bullet weight of . Standard-velocity cartridges generate near or slightly supersonic velocities. These rounds generally do not develop these velocities in handguns because their short barrels do not take full advantage of the slower burning powder. High velocity The .22 long rifle round was originally loaded with black powder. The first smokeless powder loads were intended to match the standard velocity of the original black-powder rounds. Smokeless powder is more efficient than black powder, and the cartridge cases could hold more powder. Smokeless powder loads, called "high speed" or "high velocity", were offered by the major ammunition makers, giving a typical velocity increase of 8% ( to ) while still using the standard solid or hollow-point lead bullet. Hyper-velocity Many .22 LR cartridges use bullets lighter than the standard , fired at even higher velocities. Hyper-velocity bullets usually weigh around and can have a muzzle velocity of . This higher velocity is partially due to the use of lighter bullets. The CCI Stinger was the first hyper-velocity .22 LR cartridge, and provided a significant increase in velocity and energy over standard rimfire rounds. The Stinger case is longer than that of the long rifle; about versus'' for the long rifle, but the plated hollow point bullet is lighter and shorter