To add to jbirds' excellent advice, any gun you can shoot into your target often and reliably.jbirds1210 wrote:A quality gun that has proven itself reliable.
Good modern defensive ammunition and enough practice to feel confident are the key to any concealed rig.
If you are all over the B27 with a Kimber, but you can hit the X ring at 15 yards every time with a hi-point, carry the hi-point! (Assuming it's reliable of course!)