As a suggestion......
Remove magazine.
Rotate the air bottle 1 whole turn.
Fire off excess pressure from regulator. [You'll know when it's empty.]
Remove buddy bottle completely.
Now this is the dangerous bit, so care must be taken.
Put the gun on a rest. [You may need both hands.] With the buddy bottle off and all air removed from the reservoir, draw back the bolt into the rear locked position.
Approach the muzzle, and preferably using a mirror, and inspect the barrel. Even using a mirror with moderate daylight, you should see light coming from the pellet loading section of the barrel. Get a friend to shine a torch from there if necessary.
It sounds like you may have a breech full of pellets.....