In my war with squirrels, I was trying to get more knockdown power than my RWS Diana .177. I started by getting a QB25 from Archer airguns. It looked like a lot of rifle for the money. The trigger was not as good as the RWS, but acceptable. The sights seemed cheap, but it did not matter as I was going to scope it. Once I got the scope on, I got some vertical stringing, enough that I did not feel comfortable trying to shoot squirrels with it. So, I ordered the QB78. Again, it looked like a good buy for the money. I moved the scope from the QB25, and the accuracy was good. I shoot squirrels as they show up, and these days either I have significantly trimmed their numbers or they have caught on that it is better to hide when I come home. I don't see as many as I did initially and it may be several days before I get a shot. In any case, I shot a startling raiding my blueberry bushes, and the pellet did not kill it. I either had shot that same cartridge enough that the pressure was down, or the CO2 had leaked out. So, I figured I would shoot the QB25 with Iron sights. Accuracy was acceptable, but trying to zero it, it ended up shooting high with the rear sight all the way down. I contacted Archer guns, and he suggested I file the rear sight down or get a scope. I told him I was not interested in filing the rear sight, and that the scope gave me stringing. What I really need is a taller front sight insert. He replied that they did not have any taller sights, so I am on my own, I will find some way to glue something to the front sight insert.
I am now back to where I started, shooting squirrels with my RWS.