I have a pellet gun very similar to but not exactly like that. Any markings on it? MIGHT be one of the Chinese knock offs that sell for from $20-$50 depending on exact model and specifications. Look closely for markings, may be stamped very lightly. I have one that I paid $20 for that has English and Chinese writing on it but I've heard of others with just Chinese. You will probably get lots more info at an airgun forum such as https://www.gatewaytoairguns.org/
Mine shoots horribly, worse $20 I ever spent, was going to give it to my nephew but is so inaccurate I didn't want to give it to him, wouldn't even try to resell it. Literally was doing 5 or 6 inch groups at 20 feet shooting way to the left of point of aim. I'd feel bad taking someone's money for it! I have heard with enough work on them you can make them decent shooters. I've done a little work and made it slightly better but have not had time to keep fooling with it. Good luck with yours!
I had one of those as a kid. The chamber slammed shut on my finger one day while i was putting a pellet in it, pushed the pellet through the tip of my finger and about cut the tip of my finger off. Seemed like i didn't have the bar pulled all the way down on it. Damn tip of my finger is still jacked up.
Hound_dog experienced a design problem. There should be an "anti-bear trap" safety that prevents the sharp chamber cover from slamming closed while loading. It is recommended that when cocking, you keep your hand on the cocking lever handle to prevent this problem.
My Brother in law bought a Chinese pelet rifle like that sometime around 2004. Paid $60 I think and it was a tac driver, witnessed and also shot it a dozen times. Dime groups @ 10 yards. I don't recall the brand. Even if its were the same brand, it may have come of the line 200K units later from worn out machines. You'll just have to shoot it and see how yours does. Try different ammo/wgt to see if there is something it preforms with. If still bad, at least you will have a selection of ammo for you next one. Good luck with it.
I see the same type pellet gun for sale with the same $20 up to whatever the seller can get. They primarily sell now because the wood stock makes them look higher quality and more heft then the plastic stocked rifles. Unfortunately, that is about where quality ends for most of the newer production per every review I've read.