Rob,
Sorry to have not responded earlier but I have been out of town for a bit. I'l try to answer your questions to the best of my ability.
I carry because bad things can happen anywhere and I like to be able to counter them if necessary. I have been involved in Public Safety since my late teens (it was legal to become a Reserve Officer at 18 with a high school diploma, which back then was basically an unpaid regular officer) so between that and service in the fire, EMS, and coroner's office, have seen what man is capable and willing to do to his fellow man.
Today, I generally carry what I use for my service weapon as I can conceal it well enough in most circumstances and I am generally pretty familiar with the gun. That has changed a fair bit over the years but today it is a Springfield XD in either .40 S&W or .45 ACP. I do have a very small carry piece that is a back up to my main gun or for when my mode of dress does not allow for a full sized gun. That gun is a Kel-Tek in .40 S&W. It is pretty small which makes for easy carry and concealment but that also makes it difficult to shoot well at much distance. I also have a 9mm version of this pistol that I use for cheap practice. I have carried other guns at various times from .380 ACP on up to .45 ACP and .45 Colt. 9mm (in an auto) or .38 Special (for a revolver) would be my recommendation as there is a size to fit every need and ammo is relatively inexpensive, at least compared to the other calibers. They are also quite easy to manage with most ammo and it can be easily found.
Off duty I mainly carry inside the waistband (IWB) as it fits my dress style (or maybe lack thereof would be a better description) better than outside (OWB). I also prefer to carry the gun just behind my strongside hip but occasionally need to carry it small of back (SOB) depending on the pants I'm wearing. SOB is not a preferred method as it can be very uncomfortable when sitting and the possibility of injury if you fall on your back is quite high. Around here that can happen about anytime from now to April as ice is possible during that time. You also have tripping, uneven pavement, steps, and a myriad of other possible hazzards at other times.
I have had need of my firearm a couple times when in street clothes, only once were shots fired. I now no longer hang in those types of places.
My father served in the State Department for 20 plus years and I'm guessing a part of his dislike is based on his experiences in other countries. In the ones he was often stationed, the carrying of handguns was a sign of being in government favor and those governments were not always the most benevolent. When I have asked he has not given a clear answer so at least that is what I think as he is an ardent rifle shooter.
As for ammo, well designed hollow points are the best choice. I would suggest those such as the Hornady XTP, Speer Gold Dot, Remington Gold Saber, Federal Hydra-Shock, and Winchester Ranger/STX as they have a better track record of expanding than many of the standard hollowpoints from the same companies. Whatever you decide on, run at least 100 rounds of your chosen ammo through the gun to determine reliability. Some guns will not feed some hollowpoints well and you do not want to find that out if you need the gun. It may be expensive in the short term but is something that needs to be done.
