I'm honestly a bit in the dark on this, but with the ammo availability problems going on, I've had a lot more luck finding steel case like Wolf or Tul 9mm. There are those out there who say shooting steel case in a modern polymer handgun will eventually cause problems significantly more quickly than brass. Is there any real truth to it, are there tests to back it up/counter it? I've been able to find some good articles on AR's, but not much in the handgun world.