The USP Compact 9mm/.40S&W is too big a gun for pocket or purse carry. Cops wear them as open-carry duty weapons. .38 ACP (James Bond gun) is not a manstopper, which is why nobody uses them in law enforcement or military as their primary duty arm. 9mm/.38/.357 is the smallest truly deadly caliber, and you need to be in close range. The .40 S&W was invented because 9mm was not deadly enough to save a group of FBI agents responding with 9mm/.38/.357 calibers to a bank heist in the late 1980s that went wrong. Kahr makes some very good pocket guns, and .38 revolvers work fine as well. I would feel exposed with anything smaller.

1986 Miami Bank Shootout