Use of Pistols in Combat

[zackmann08]

So I have a question for any and all members of our armed forces out there. Ive been watching a lot of these "raw" videos from Afghanistan (http://www.youtube.com/user/FUNKER530), really worth checking out by the way, and I had a question. How often, if ever, do you use a sidearm in combat? In all the footage I've ever seen in combat, be it news reels or this raw, helmet cam stuff, they are always using primary weapons (which obviously makes sense). I'm just wondering how often do you ever use your pistol? Is it solely a last ditch "I'm out of ammo for my M4" type thing? Or are there certain situations that call for a pistol instead of a primary weapon?

Thanks for the info.