FYI attempts to sell a gun with built in fingerprint lock have been blocked by the NRA and gun lobby since availability of such a "smart gun" would trigger a New Jersey State law to require biometric locks on guns to save children's lives. So far all attempts to put such a gun on sale have been blocked including by use of death threats.
There is an alternative which is an after market trigger lock called Identilock https://getidentilock.com/collections/buy-identilock
One other point - in the US you can be compelled by court order to provide your fingerprint to unlock something. If you use a password or PIN code them you cannot. You could be held in contempt of court and jailed (potentially indefinitely but probably not actually) but that's about it. Although never underestimate a President who is openly friendly to torture from labelling you a terrorist or enemy combatant and torturing you until you give it up.
Great comment! I Agree with You....
However i was only pointing out the various Use of Biometric technology weather the Guns are widely used or not isnt the basis of my post.
Secondly If you have nothing to Hide, you definitely have nothing to be afraid of..... If i reside in the US tho i'd take my chances using the technology over using a PIN code or password regardless because the benefits are numerous.