Heck Yeah! match a Defense ammo to your range target ammo! when you know your gun you trust your gun!
I know I often roll my eyes about people who complain about the high cost of carry ammo with respect to periodically cycling through their carry gun/magazines.
And, honestly, I still do...going through a box (or two) a year isn't a big deal.
However, I DO feel where the high cost of self-defense ammo in recent years really sucks is when you're first feeding a new, potential carry, pistol trying to find a quality SD round that cycles reliably and has the same point of impact as your target ammo.
I like to try at least a small sampling of different brands, maybe three or four. Preferably the same mass as my target ammo, but maybe something else close to that.
With SD ammo very commonly sold in 20 round boxes, with prices ranging from $16 to $36 a box (some deals better if you can find it in 50 round boxes, or on sale), that adds up quickly.
Picking $25/box as a reasonable average, just to crunch some numbers, four brands is at least $100. Add a couple different bullet masses, that adds another $100. If you assume some base number of rounds to shoot for reliability testing (say, 100 rounds just for this posting), that multiplies this by 5, adding up to $1,000. Which means you've got to be smart about this.
With all that said, here's my approach to this:
First of all, quality SD ammo isn't hard to find these days. Nowadays, we can look up performance information from many different sources because there are a TON of shooters out there eager to do this and post the information. Not only that, but this isn't the 60s and 70s...decades of a highly competitive market has produced several well known brands which produce quality SD ammunition. Which means that pretty much any well known brand will be a perfectly suitable round with respect to terminal ballistics.
Your pistol's
basic mechanical reliability is something that you can very easily verify with much cheaper "target" ammunition. If you have magazine problems, slide problems, extraction problems, etc. you're very likely to find out about it no matter what ammunition you shoot, so it might as well be with less expensive target ammunition.
Many SD rounds have velocities that are on par with that of much of the target ammunition out there with the same bullet mass. That means you're likely to have points of impact very close, if not indistinguishable, to that of your target ammo. For example, much of my 9mm target ammo is WWB in 115 gr, which has a muzzle velocity of about 1190 fps. My chosen Speer Gold Dot 9mm in 115 gr has a muzzle velocity of about 1210 fps. I can't tell the difference on the targets between the two.
SO...
1. Shoot a lot of different TARGET ammo initially to see if you have any basic reliability issues.
2. Limit your initial purchases of SD ammo to quality brands with the same bullet mass and velocity as your chosen target ammo.
3. Buy no more than one box of SD ammo that meets #2 above in however many brands you wish (based on desire, money, etc.).
4. Shoot your various brands of SD ammo, paying particular attention to how they compare on the target with respect to your chosen target ammo. If you have any mechanical issues, note them, especially with respect to the brand. (If your gun doesn't like something, then quit trying to feed it the same thing...that's just asking for frustration.)
5. Of the SD ammo that doesn't give you any problems AND which shoots very close to your target ammo, buy enough to satisfy your needs/desires to further test and to carry.
KEEP IN MIND that you do not have to do this "all at once". You can simply buy a single box of ammo under the criteria above and shoot it. If it functions well and hits the target where you're aiming at, you've got a winner at that point. Now you can buy more to test reliability and have something to carry. You can always expand your horizons later with the occasional box of something different here and there.