I want to carry ammo that I understand thoroughly. It needs to have been recommended by a competent authority, be in in wide circulation, work day and night and in the heat and the cold in my carry guns, fire a projectile that penetrates enough but not too much, have sufficient but not excessive energy for self-defense purposes, and be consistent from batch to batch.
As a result, I have chosen to carry factory ammo that a major manufacturer says is suitable for self-defense purposes (.45 acp Winchester Ranger T 230 JHP). I have a decent supply of this ammo and have tested it for proper function in my carry guns.
I've documented that the bullets in this load travel at an average of 851 fps from my carry guns, with a standard deviation of 17 and 370 ft-lbs of energy. These numbers do not vary significantly from lot to lot. Every year, I shoot large numbers of handloads that use 230 gr LRN/FMJ/JHP which travel at about this same velocity.
Periodically, I fire the rounds that I have carried for a while and then load fresh ammo. When I load fresh rounds, I document this action by writing the date on the ammo box the rounds came from (which includes the manufacturer's lot number), and store the box in my safe.
I've tested the Rangers at night, and have found that the powder used is extremely low-flash (especially when compared to my handloads). I've verified that the Rangers work reliably in the heat and in the cold. I've seen the results of tests conducted in calibrated gelatin, firing through layers of denim (
http://www.youtube.com/watch?v=U-K9krp7fnE). Penetration was 14 inches, bullets expanded to .74", with 100% weight retention.
For those of you who know your carry ammo this well (be it factory or handloads), I say BooYa! If you don't, though, run some tests, and see how it performs. You'll have fun! And you might be surprised by a few things.
If you do this work, nothing about your carry ammo will surprise you (if, God forbid) you ever have to use it for real,
and you'll be able to respond effectively with documentation to most ammo-related questions that anyone might ask you afterwards. In my mind, these are both priceless benefits.