single action 22 mag/LR pistols

Question
For many years I have read of the issues regarding minimum caliber for protection and the auto vs revolver.  People will have their opinions, and I have mine, so let's move on to an issue where there seems to be more agreement--that of a second, concealed back-up firearm.  In this case, fewer of the experts and magazine writers object so strenuously to these little 5 shot revolvers.

But my question is not to find another opinion about them.  What I would like to know is why no manufacturer has been able to make such a micro revolver in double action.  Even if it added a tiny bit of weight and size, it would seem to me a better solution to the pocket gun question.

Answer
I am with you but the smallest DA weapon is about he size of the airweight .357 revolver or some smaller .380 semi auto - all guns were single action in the beginning so it was the only option- smaller guns that DA tend to be easier to fire and thus increases the chance of a AD (accidental discharge) - so it may be liability or demand. It would cost more and not sure the demand is there for the research and development - if I am going to carry a single action small gun I will opt for a .38 special with only two shots in a derringer over five shots of a .22. - imo.