I was a Federal Investigator for over a quarter of a century (Darn, that sounds long when I write it that way), working on the Southern border. Pocket carry was, in the work I was doing, the most efficient way for me to go.
I carried, and still carry, a custom made 9mm - a LaFrance NOVA. This is a STAR BKM, cut down smaller than a Walther PPK, but still full 9mm. In fact, STAR came out with the Firestar after they saw what Tim LaFrance was doing, but the Firestar uses a steel frame, which makes it too heavy.
And at 6' and 200#, I can conceal it in the front pocket of a pair of jeans.