You have to find a repair center.
it depends on the model. See the link below and select you model to see the diagram.
Gun shop, gun show, e-gunparts
The BSA Mercury was made between 1972-1980
BSA cadets were made between 1946-1959
BSA made several different air rifles. Unfortunately you did not state the model number and that is critical. You could try to contact BSA and ask them. see the link below.
See the link below. When it opens select your model for the drawing.
I suggest you contact BSA Directly at the link below. They may be able to help you.
I suggest you contact BSA directly for the best answer. See the link below.
There are a number of places that an individual can find BSA rifle scopes. Some of the places you may want to try include BSA Optics and Air Rifle Scopes.
I would direct this question directly to BSA at the link below. They would have the best answer.
I suggest you contact BSA directly in the UK. See the link below..