Lyman 57 receiver sight removal?

[Caprock]

I came into a nice 722 Rem 300 Sav fitted with an older 57wjs receiver sight that I want to move to another 722. I pushed the button to release the slide and it won't give so I can access the other mount screw. It's not rusted or frozen up. Advice please!!!!!

[Hiwall55]

Try to use the screw to move it up and down a few times then try the button again. I had to do this to one of mine

[Caprock]

Thanks. Finally got it loose. It had the Outers Gun Oil Syndrome.....50 years worth set up like concrete.