I have a Barska 3-12x40 mil dot AO on my nitro piston air rifle. It was on 2 springers prior to that and it still works fine. The nitro came with a Centerpoint that went into the trash after 10 shots. It was not even worth sending in for warranty. I have one of the Barska 1-4x24 mil dot scopes mounted on my wife's S&W 15/22. She has trouble with red dots like which dot am I supposed to use. The diopter adjustment takes care of which dot. Picked it up very cheap with offset one piece rings. They work on 22lr if you are shooting up to 50 or 100 yards. I would not put a Barska on a center fire. If you are shooting out to 300 yards which is a growing sport you need something a lot better. Long range 22lr (300 yards) is starting to be big business. Precision rifles with 20 moa bases are one aspect.