Pellet
From Wikipedia, the free encyclopedia
A pellet is usually a small, compressed, symmetrical and hard chunk of matter. Ex: Wood pellets, Ore pellet, etc.
A pellet is also the term for a non-spherical projectile designed to be fired from an air gun. Pellets differ from bullets used in firearms because of the pressures encountered; firearms operate at pressures of thousands of atmospheres, while airguns operate at pressures as low as 50 atmospheres. Firearms have sufficient pressure to swage a slightly oversized bullet to fit the bore to form a tight seal, while airguns generally use a slightly undersized projectile that is designed to obturate upon firing to seal the bore and engage the rifling. Since pellets may be fired through a smoothbore barrel, they are often designed to be inherently stable, much like the Foster slugs used in smoothbore shotguns.
The "diabolo", sometimes called wasp waist pellet is the most common design found today. The diablo pellet can have a flat, round, hollow or pointed tip, followed by a taper to a thin waist. From the waist back, the pellet is hollow, and flares out to full diameter. The head, or solid part in front of the waist, is usually sized to fit the bore just touching the rifling. This keeps the pellet centered in the bore, while keeping the friction low. The skirt is thin and made of a soft, deformable material, usually lead, although some pellets use tin or even plastic. When fired, the skirt will obturate to fit the bore and provide a good seal, and engage the rifling, thereby providing a spin. In a smoothbore barrel, the skirt will still flare to provide a tight seal, but since there is no rifling the pellet will not spin. In this case, the solid head in the front and hollow skirt in back will prevent the pellet from tumbling and provide some accuracy.
Pellets are designed to travel at subsonic speeds. High velocities can cause light pellets to deform or even break apart and the transition from supersonic to subsonic will cause most pellets to tumble. The closer a pellet gets to the speed of sound the more unstable it becomes. A few companies have addressed this issue by manufacturing heavier than normal pellets for use in high powered air guns. These pellets travel at a reduced speed because of their weight and can be more accurate.
A pellet is also one of numerous small, dense spherical projectiles fired from a shotgun shell. Collectively, they are called shot.
In centrifugation, a pellet is the concentrated component of a mixture that had been centrifuged. The supernatant is the remaining solution.
Pellet may refer to:
- Animal Feed Pellet
- Iron ore Pellet
