Taurus has issued a recall on some GX4 pistols that could discharge when dropped. They have set up a website where you can easily find out if your GX4 falls under the recall by entering your serial number.
Here is the notice from Taurus:
IMPORTANT SAFETY NOTICE
Some GX4 pistols assembled and sold only in the United States may, under certain circumstances, discharge when dropped.
Safely unload and stop using your GX4 IMMEDIATELY. Failure to observe this warning may result in injury or death to you or others.
Enter your pistol’s serial number.
The website will promptly let you know whether your GX4 is subject to this Notice. The serial number is located on the rear of the pistol. Follow the Website’s instructions.
If your GX4 is NOT covered by this Notice, please disregard it.
You may also contact us by phone at 229-515-8464 by online submission at https://www.taurususa.com/support/service-request email or by U.S. mail at Taurus International Manufacturing, Inc., 100 Taurus Way, Bainbridge, GA 39817.
If you no longer have this pistol, please forward this notice to the current owner.
Taurus will inspect, repair, if necessary, and return your pistol to you as soon as possible, FREE of charge
We understand that this is an inconvenience for you. Thank you for your patience and cooperation.