FYI, JOAT, I didn't buy this new from China, so there's no telling how
many times it was fired before I bought it. The screw hole is worn and
gets progressively worse with each firing. (But thanks for your
skepticism, because I'm sure you know we're all liars here on the web.)

Thank you to everybody for all your help. I still haven't decided if
it's time for me to buy a new stock altogether. I had no idea there
were so many repair options.