Not in any gun I own. They make gun locks that are easy to disable when a gun is needed. Before all the safety locks came out, and it was mostly DA revolvers a padlock was all that was needed. Just put it behind the trigger guard. This was how I kept my guns at home when I was not home. The rest of the time the kids knew to not touch the gun. I can just see it "Please mister burglar wait will I disengage the safety cartridge?" "Now where did I place that rod?".

ETA

What makes them think the child will not open, and rotate the cylinder before pulling the trigger.