A smart gun, with a little screen on it.
First, pull the trigger, then a coat of arms appears on the screen, and if you describe it correctly, the gun fires.
Sort of heraldic counting to ten, although for the more tricky ones, possibly before the sun goes out is the best than can be hoped for...
(shooter) I'm trying to..
(gun) I was only speaking metaphorically. Ok, what's the coat of arms?
(shooter) Well, it's got a bend sinister..
(gun) ermm are you sure about the sinister?
(gun) Ok, let you off this time, how about the trefoils?
<cuts to much further on into the dialogue>
(gun) put the hammer down...I'm in a titanium housing, it'll do nothing..