It sounds like one of the seals has gone bad. I suggest you do a web search on "air gun repair" and locate a shop near you to replace all the seals. If you are in the USA, See the link below.
You will need a .177 caliber cleaning rod to push the pellet back into the loading breech from the barrel.
This is a break barrel air rifle. Push the barrel down to open the breech and then load a pellet in the barrel. Pull the barrel all the way down to load the tension on the spring then close up the barrel. It's ready to shoot
It depends on the model, but it usually is on the barrel somewhere or the breech below where you load the pellet or BB.
The breech area on any gun is the area where the pellet / bullet / BB is loaded into the barrel. The bullet stays here until the trigger is pulled.
You can load it (One shot at a time) with a pellet on top. Just open the breech and place a pellet in the barrel. Or you can load several BB in the left side trap door. See the link below.
The Slavia 622 is a .22 caliber pellet rifle not a .177 caliber rifle. It is a single shot Break barrel rifle. The rifle is a spring piston shooting system. To load and cock the barrel you simply push the barrel down (Break the barrel) all the way until you feel it cock. Load a .22 caliber pellet into the rear of the barrel (Breech) and make sure it's snug flush with the barrel. Load it with the skirt facing out and the dome in the barrel. Then bring the barrel back up into position and let it snap into place. AIM FIRE!
First, if you are not a grownup, get the help of a grownup. This can hurt you if done incorrectly. OPEN the action, and place the weapon on SAFE. If it is CO2 rifle, remove the CO2 cartridge. Place the rifle in a support, such as a padded vise, with the muzzle pointed in a safe direction. Without putting your body in line with the barrel, insert a cleaning rod into the barrel until it touches the stuck pellet. GENTLY tap the rod with a plastic mallet until the pellet is pushed back to the breech (rear of barrel). Did you read the first sentence?
Usually just below the loading breech.
Is this a Pellet, BB or airgun? If it's a pellet or BB gun you can use a .177 cleaning rod down the barrel to push the Pellet back out of the barrel into the breech. Make sure the pistol is not cocked. I suggest you look up "air gun repair" on the web and take it to someone who repairs airguns to have it fixed.
Loading the Crossman 766 Air rifleThe Crossman 766 fires a single .177 air rifle pellet, or multiple 'BB's. The .177 pellet is loaded in a breech on the righ hand side of the action. The breech is exposed by pulling back a lever with a finger sized hooked lever. The pellet is carefully dropped in with its front facing forward and the breech lever carefully pushed forward and locked down. Great care must be taken in case the pellet is disturbed as it slides into the neck of the barrel so a visual inspection of the pellet as it goes in is a good idea.The rifle needs to be charged. This can be done either before or after loading the pellet. To charge the rifle, grasp the wood-look plastic piece under the barrel at its near end. It will come away from the barrel, hinged at the front. This is an air pump and repeatedly fully opening and then fully closing the lever will charge the weapon. Less than two pumps will result in a pellet jamming in the barrel. 5 pumps will give good results for tin cans and 10 plus pumps will kill vermin at 25 yards...The BB's go onto the base of the pistol grop behind the plastic cover found there, which slides forward.. The long thin slider on the left hand side of the action has something to do with the BB's too....Remember if an air rifle shoots pellets use pellets because bb's will mess up the guns accuracy.
use a .177 cleaning rod to force it back into the breech.
The Crosman 120 is a rifle not a gun. It is a break barrel. Cock the barrel all the way down and load a pellet into the rear of the barrel. Pull the barrel back up and it' is ready to fire.