Train with what you carry... Including ammunition
I see a lot of people at the range shooting the cheapest target ammunition they can find. Don't get me wrong; training ammo can get expensive depending how many rounds you fire on a given range day. I am not saying go out and shoot up all of your personal defense ammo at the range but use something comparable. Without getting deep into ballistics let me explain. If you carry a 9mm, with 147 grain, 950 *f.p.s. personal defense ammo, don't go to the range and shoot 115 grain, 1,180 f.p.s. target ammo. I know it may seem hard to believe but they may not have the same point of aim on the target. You may not be able to find ammo with the exact specifications but you can get close.
Something else that is very important to do also is to use your carry holster when you are on the range. You need to be comfortable drawing and holstering your firearm from your carry rig; don't just pick it up from the bench and start shooting. Also, you should fire a magazine or two of your personal defense ammo through your carry gun. This will not only ensure it functions properly in the firearm, but it will also give you a better understanding of its point of aim compared to target ammo.
I am not going to get into what caliber, bullet weight, f.p.s or manufacturer you should or shouldn't use in this post; plus I believe that has a lot to do with personal preference. I will say that in recent studies of gunshot fatalities (2011 Article); the size of the round has less to do with it compared to proper shot placement. So with that being said choose a gun and ammo you can consistently and accurately put on target; including well-aimed follow-up shots.
If you take anything away from this post, please take this; I must train with what I carry. I need to draw from my carry holster and engage my target. I need to match my target ammo as close as possible to my personal defense ammo. I need to fire my personal defense ammo through my primary weapon to ensure proper shot placement and functionality.
Here is what I use:
Target: CCI Blazer Brass, FMJ,115 grain, 1,125 f.p.s.
Personal Defense: Fiocchi Extrema XTPHP,115 grain, 1,150 f.p.s.
.380 Backup Gun (BUG) ~ Backup Guns (BUGs) To Carry or Not to Carry? ~
Target: CCI Blazer Brass, FMJ, 95 grain, 945 f.p.s.
Personal Defense: Fiocchi Extrema XTPHP, 90 grain, 975 f.p.s.
* F.P.S. - Feet per Second, referring to muzzle velocity