good thing where accuracy is concerned. The commonly used airgun diabolo pellets have a poor ballistic coefficient, and quickly lose velocity; when they drop below the speed of sound, they will often tumble. However, high velocities sell airguns; if accuracy is desired from these high velocity guns, then heavier pellets should be used to keep the velocity down. This will provide not only better accuracy, but better downrange preservation of velocity and kinetic energy. Pneumatic Pneumatic systems use compressed gas for power, usually compressed air. This air may be compressed by the gun for each shot, in a single stroke or pump (multiple stroke) gun, or it may be precharged by an external compressor. A single stroke system, as the name implies, uses a single stroke of the pump to compress a cylinder full of air, which is then all used for one shot of the gun. Single stroke systems are both inexpensive and capable of high accuracy due to the simplicity and consistency of the single stroke design. The downsides are the low power provided, though this is not a handicap in standard 10 meter airgun target shooting. When Daisy introduced an inexpensive single stroke pistol, the model 717, in the late 1970s, American Olympic shooter Don Nygord demonstrated the potential of the design by shooting an accurized version in a California State air pistol championship, and winning the gold medal. The (at the time) US$40 Daisy, with a better rear sight and an adjustable trigger added, shot as well as the US$400 Olympic class air pistols it was competing against. More powerful is the pump system, which is a slightly more complex version of the single stroke design. Rather than leaving the air in the piston when compressed, the pump airgun has a reservoir to contain the compressed air, allowing multiple pumps to be used, typically 2 at a minimum, up to 10 pumps for full power. The ability to vary the power, however, is the pump airgun's major disadvantage when it comes to accuracy, as it makes it very difficult to get a consistent charge. The increased power of a pump airgun makes it an attractive choice for many shooters, and there are steps that can be taken to improve consistency, such as modifying the air chamber so that not all the air is exhausted in a shot. The last type of pneumatic airgun is the precharged