The way I look at this is that more then likely if I ever had to pull my CCW the threat will be pretty close to me, close enough that pull and fire is a very likely scenario. Shooting from the hip with one hand or aiming with one hand. I personally feel like at a self defense distance just about any hand gun caliber is enough to STOP a threat. However personal preference plays a roll into whatever I or you feel like is enough stopping power. I carry some form of .38 special most of the time (K or J frame Smith) and will carry .380 sometimes (ppk/s) I personally would not carry anything less. So for me .380 is the minimum for my self defense standards. Most likely us non LEOs will never have to pull or use our CCWs so carry what makes you happy and your comfortable wearing all day. This is all just my 2 cents, I am not trying to argue or disagree with anyone on here.