You have to find a repair center.
It's the top portion of the gun that slides back and re-loads the airgun with the next shot when the gun is fired. The slide is literally blownback by the gas in the gun. It slides forward as it re-loads the chamber, all with the pull of the trigger.
Your best bet is to go on-line and do a search for "Airgun repair" and locate a shop near you for repairs.
For a rifle that fires between 800 & 1000 FPS you should set your target at 60 feet. You will have to adjust for rifles that shoot at a slower FPS.
Only if the airgun has a scope rail designed into the gun. You will also need an airgun scope not a firearms scope.
The highest velocity of an airgun is that of Evanix AR6 pistol which is 1000 fps.
Haenel model 10 (X) This model was made between 1930 -1939. It would be worth around $105 + depending how good it is. Missing the trigger guard will drop the value slightly.
First you have to let us know What Model Crosman Airgun or Rifle you are talking about. The model number is printed on the side of the barrel. Give us this information and re-post the question.
Airguns normally shoot metal pellets. A rifle cargridge has a built-in gunpowder charge to propel the bullet when the powder explodes. An airgun compresses air in a chamber, when you pull the trigger the air is released and takes the pellet with it.
The address of the Daisy Airgun Museum is: 202 W Walnut St, Rogers, AR 72756
$55,000
Air is used to propel the projectile.
It depends on the model