A lot of them need tweaking from new. I actually had to do more to my Winchester-Daisy 1000x to get it to shoot accurately and repeatably. Main issue were the stock screws--- they were all loose, and they'd work loose again after shooting it a while. A little Locktite took care of that. Mine was made in Brazil--- usually those are pretty well done, but the press fit front sight was also loose, so I had to get a new one. My barrel also had something dried in it at one point, so I worked on it with some Bore Brite until I got that out. It wasn't dip-lubed, like the cheap Chinese guns, is about all I can say for it. After doing all that, and cycling a few hundred pellets through it, it finally has some pretty good accuracy.
Another thing about airguns that seems a little peculiar at first, is they are less accurate if they push the pellets supersonic. That pellet flies a little like a badminton bird, with that skirt on it, so it wobbles when it breaks the sound barrier. Noisy, too. My recommendation is to get a gun rated for as fast a muzzle speed as you can afford, then get pellets that are heavy enough to slow it down to subsonic. (Speed of sound is around 1050-1100 fps, if I remember correctly.) It will be more accurate and hit harder with the heavier pellets, and won't be as loud.