Choose a biometric gun safe that will allow you to store at least 10 different fingerprints. This will allow you to add your spouse, or other responsible adults, to the memory in case of an emergency. You can always choose a safe that allows more.
Know the "false accept rate" of the gun safe you plan to buy. This is the percentage of fingerprint the sensor will allow to be incorrect and still open the safe. Most fingerprint gun safes have false accept rates that vary from 0.0001 to 0.1 percent.
Learn the "false reject rate" of the gun safe you plan to buy. This is the percentage of time the sensor will not let you access the safe, when producing the correct fingerprint. Most biometric handgun safes have a failure rate that varies from 0.00066 to 1.0 percent. You want to purchase a safe that falls in this range.
Choose a biometric gun safe that has a backup key, in case the fingerprint identification fails. Any number of issues can give a false reading, such as cuts or abrasions. It is best to have a backup key stored in a safe place, to assure 100 percent accessibility at all times.