See: https://oag.ca.gov/firearms
Click Denied on the bottom left and look at the instructions the CA DOJ gives people.
Bold added by me.
Click Denied on the bottom left and look at the instructions the CA DOJ gives people.
If your DROS application is denied, you will receive a letter from the DOJ Bureau of Firearms within two weeks. The letter will explain the reason and instructions on how to get a copy of the record that resulted in the denial of your application. There will also be instructions on how to dispute and correct information in your record you believe is wrong. DOJ staff cannot discuss your record over the telephone. Therefore, it is recommended that you get a copy of your record and follow the instructions for disputing inaccuracies. You may also wish to retain an attorney for legal advice and who can best represent your interests on how to restore your rights to buy firearms.
If your DROS application was denied based on a Federal Brady prohibition (e.g., out-of-state conviction, illegal/unlawful alien, military dishonorable discharge, out-of-state mental health record, etc.), you can appeal the denial of your application directly to the Federal Bureau of Investigation National Instant Criminal History Background Check System (NICS). When discussing your situation with NICS, you must include the NICS Transaction Number (NTN) associated with your firearm purchase as referenced in the denial letter sent to you by the DOJ Bureau of Firearms. You can appeal directly to NICS by downloading the NICS appeal brochure and following the instructions found at NICS Appeals page.
If your DROS application was denied based on a Federal Brady prohibition (e.g., out-of-state conviction, illegal/unlawful alien, military dishonorable discharge, out-of-state mental health record, etc.), you can appeal the denial of your application directly to the Federal Bureau of Investigation National Instant Criminal History Background Check System (NICS). When discussing your situation with NICS, you must include the NICS Transaction Number (NTN) associated with your firearm purchase as referenced in the denial letter sent to you by the DOJ Bureau of Firearms. You can appeal directly to NICS by downloading the NICS appeal brochure and following the instructions found at NICS Appeals page.

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