I've never been a fan of really small guns... Hard to handle really well & control, especially under pressure in a panic situation... In the summer I carry a compact (M&P not sub) 40S&W or the Colt Officer's ACP... I've been through the Front Sight 4Day Defensive handgun course with it and was able to effectively draw and handle it for personal defense... The rest of the year the weather here allows me to carry a full size pistol (or close to it) so I do.. 45ACP as I'm not really a fan of small calibers either... There are a collection of really good videos on YouTube done by a user TNOUTDOORS9 that show bullet expansion. He does a pretty good job...