Under fear and stress of a deadly encounter, you must be able to effectively respond within a very few seconds or you may be beyond caring. Unless you are capable of making your semiautomatic ready, without thinking, the revolver may be for you. While certainly no powerhouse, it is very easy to conceal and exceptionally easy to carry due to its light weight. Even loaded with expanding high-performance ammo, it is not the primary weapon of choice if I knew an altercation was coming, but is always at hand. For those wanting to carry a larger weapon or those more in harm's way, a reliable semiautomatic no smaller than 9mm has much to offer.
Several makers offer quality single or double-action autopistols.
Take your choice, but whatever you choose, become intimately familiar with it. These service style pistols are easier to reload, fire accurately, and lend themselves to more varied uses than the small defensive revolver. Yet, some within the shooting community automatically look down on this group of shooters. Give yourself a break. If you get the opportunity to shoot with some of these enthusiasts and they're safe, jump on it.