To best answer your question, look at the history of law enforcement weapons. Many years ago the 38 was the choice of most police departments. Then came the 38 special which evolved into the 357 magnum. Then the semi automatics came on to the scene and and the 9mm was the most popular.

After many shootouts in which the good guys were carrying the 9mm and the bad guys were not stopped immediately, there was a movement to go to a more powerful cartridge. The FBI did extensive research and decided that the 40S&W was the round to use. That is now one of the most popular rounds used by law enforcement. During all this time thought, many of the elite forces were carrying the infallible 45 which was the major US military sidearm for many years. This was a single action pistol. There now is a multitude of double action gun available in all calibers and this style is the most popular for the average person who does not do a lot of shooting.

If the 22 were a real good bad guy stopper then most law enforcement agencies would use it just from the cost factor. But they don't. The 22 is not adequate in a gun fight. You never take a knife to a gun fight and the 22 is one step above a knife!

My favorite is the 1911 45.