For range practice, shoot the cheapest ammo that will reliably feed and function in your gun.
Don't worry about the ammo being "dirty."
- It's not the cause of a gun's mechanical woes.
- It's not the cause of a shooter's problematic and sub-par performance.
Go to any of the larger training classes, and you'll see that the vast majority of shooters simply shoot whatever they could get cheapest at the time. You'll even have fellow students with custom 1911s and 2011s or other upgraded/modified handguns that are literally $3 to $5K, and yet, they'll put Tul/Wolf or Blazer aluminum through them. They'll shoot graded exercises with the same: no one runs back to their range bags to dig out their special graded-exercise/testing "match" ammo. :lol:
Why?
Because aside from your gun literally not liking the particular ammo and failing to properly function with it (i.e. it fails to cycle and/or feed), the rest of that stuff is really just excuses.
Yes, if you're shooting to find out the absolute mechanical capabilities of your weapon, you should be using excellent ammo - but honestly, if you're doing that, you'd be shooting the gun from a vice.
The only exception here really comes in terms of either range requirements (i.e. disclaimers of "frangibles only," "no bimetal, steel core, non-brass cased ammo," etc.) or if you desired to use a specific load to better mirror your defensive ammo in terms of recoil impulse, muzzle blast/flash, and/or smoke.
In terms of defensive ammo:
Best Choices for Self Defense Ammo
^ Note that
DocGKR specifically mentions that the list is not in any kind of order: all the list notes is that each of those loads meet the requirements set forth by the FBI.
Instead, one should vet their chosen ammo in their own gun - because each gun, while mass-produced within tight tolerances, still nevertheless carry unique variations in that tolerance. What that's stacked with the tolerances of the ammo, there are just going to be those weird and unpredictable incidences where one unique gun just will not reliably feed and/or fire X or Y ammo.
Vet the ammo for reliability in terms of feed and function, and take note of its subjective recoil characteristics as well as muzzle blast/flash and smoke (both important in low-light), and also look at how readily available the particular ammo may be in your local area as well as how reliably it's stocked by your favorite online vendors. Take cost into consideration as well, as you will need to routinely practice with this ammo, which can have not only different recoil and blast/flash/smoke characteristics from your favorite practice ammo, but also even external ballistics.