10mm

[Sudden]

I still believe that you have to go with what you are most comfortable shooting. Yes it may have more knock down power than a 9mm, however if you are not comfortable shooting it and are wild with it at the range, I dont think it would server you well to have to use it under pressure. To me, what you are comfortable holding, shooting, and have no issues with at all should be what you carry. If you are very comfy with the 10mm then by all means go right ahead. I am just saying that to me, I would rather carry a 9mm that I am very comfortable with and very accurate with than a 10mm that I am not so comfortable shooting.

Also very good points about the 10mm being hard to find. I have heard from guys at the range that it is very rare to find 10mm in most places.

100% Correct on comfortable shooting. I am comfortable shooting the 10mm S&W BUT it is a gun that comes off target when fired and has to be put back on between rounds. That is not good for anyone! It isn't the best gun for "two to center of mass" in a hurry. That makes it a problem for self defense. I would prefer it to my 9mm if someone did a driveby on me and I was shooting back at the car.