For me it might be either a 22 automatic or a double action 22. In my memory I was good with them, but it has been so long since I have been able to find 22 ammunition that I could afford that I don't dare use what I have. Then maybe I am wrong. Maybe I was never as fast as I remembered. Regular shooting tends to bring me down to earth.
The rapid fire trick that has always fascinated me was in Elmer Keith's, book sixguns. He describes stacking three glass bottles, shooting at the bottom one, and breaking the other two as they fell down. He said that a 22 lacked the power to break the bottles cleanly enough, and a 38 was too slow. The only gun he could do it with was a K-32. I always wanted to try that, but there aren't too many places left where you can break glass without feeling guilty, and I never got my hands on a K-32. He wrote the book in 1936, which meant that he must have used a pre-war K-32. According to the figures published now only 96 of those pre-war K-32s existed. Since Smith & Wesson didn't advertise how few of those guns they were selling, I doubt if Keith knew just how rare a gun he had.