Was reading an article today in a Gun Mag. It mention that for a 3" barrel 9mm gun you should not use 147 grain bullets for PD (currently I have the Winchester Ranger SXT 147 grain). What he recommend were the 115 grain Cor-Bon DPX JHP. This was because of the 800 fps or so velocity range and the bullet not expanding. What are your opinions on this subject? Is he right? Will my current PD ammo not be as effective or do it's thing, if not shot from a longer barrel? Help?