I'm not terribly sure to be honest but I would take it back to where you got it from and try to return it.
You can purchase a slide hammer a ACE
Technically, suitable ammo is loaded into magazine. Magazine is inserted into pistol. Slide is pulled back then let go, chambering a round from the aforementioned magazine. Trigger is pulled, causing hammer to move backwards via the trigger bar. Once past point of release, hammer falls, striking the firing pin. Firing pin moves and contacts primer of round, causing detonation of the powder, forcing the bullet forward through the rifling and exiting barrel. Firearm unlocks, casing is extracted and ejected, hammer is cocked, slide catches another round and forces it into the chamber of the barrel. Slide returns to forward most position and the whole process repeats.
Simple: With the Safety On. Slide a cleaning rod down the barrel to dislodge the pellet from the loading port. Yes there are cleaning rods for pellet guns. They are 177 caliber.
The 15XT is a BB pistol, like the name says. It is not a Pellet pistol. If you can't force is back into the BB holding slide then you might as well buy a new pistol. You will need a .177 caliber cleaning rod and use it to push the pellet back into the BB loading port
Hammer on, hammer of and Slide
condition 1
A Slide Hammer..............
Best to take it to a good gunsmith.
nothing..... just re-cock the hammer before replacing the slide
The Beretta 92 series pistols have a chamber indicator on the top of the slide. It's basically a small rectangular square which protrudes from the top of the slide when there is a round present in the chamber. Simply running one's finger over the top of the slide will reveal whether or not this chamber indicator is protruding (thus indicating a round in the chamber if it is protruding, and indicating an empty chamber if it is not).
Slide hammers can be bought in good tool stores, particularly stores that specialise in auto-body and sheet metal work. - I have never seen a slide hammer used in carpentry.
Pull the slide to the rear, and look into the chamber. Some Beretta handguns also have a chamber indicator at the top of the slide, which is simply a piece of metal which protrudes from the top when a round is in the chamber. However, this is no substitute for a visual inspection when clearing the weapon.