There are devices on the market that use a special screw that can be opened using simple household tools and loosened and opened. The trigger lock not secured properly, you can still get your finger behind there and fire the gun. With this trigger lock, the gun can still be fire by pulling back. This is a typical cable lock. These are used by passing a cable through the firearm, latching the cable to the lock which prevents you from loading the magazine and pulling the trigger and operating the weapon in a normal manner.
Simple drop can cause the lock to open.
With just a regular pair of cable cutters, we can cut this lock and fire the gun. A simple impact can open this type of lock. With a simple impact, we can cause this type of lock to open. Home Safe campaign for safe firearm storage. Law enforcement agencies distributed the gun locks free of charge from September 1999 through October 2000.