I do not have any Military or LE experience, but my neighbor George Statler most certainly does. Although he does not speak about it very often, he was with the Airborne Rangers in Vietnam. He was what was known as a "Tunnel Rat". Although he was issued a 1911, which is in my opinion the very finest handgun ever created, he chose to carry a Colt Trooper in .38spl. when crawling around in the dark underground trying to find the enemy. He still carries it to this day. He apparently used it to good effect and once told me he felt it was more reliable and easier to engage the enemy with in very close quarters. He has two bullet wounds, three Bronze Stars, a Silver Star, and a Purple Heart with clusters, plus a commendation from the Republic of south Vietnam, all displayed on the wall of his den, so I guess that he probably used the gun a few times.
I am fully aware that this sounds like some made up "Rambo" story, but I assure you that it is not. George is one of the finest men that I have ever known.