If it was not safe the commercial manufacturers would not sell it. Since prices of ammo are still high it's nice to see ammo that costs less. If you don't need the brass for reloading there is no reason not to save the money or shoot more for the money you spend.
I have a Sig p238 .380 nice little gun. BUT....steel ammo and any ammo other than Winchester or Remington jams the slide up....I mean solid...can't get it to fire, or eject the magazine.....With the pistol pointed down range with the hammer back , i need to beat the top of the slide with the palm of my hand, till i can finally rack the slide back to eject the cartridge..Other than .38 for my S&W revolver , i'd stick to better named brass ammo..
It would be something to check. The indoor range I go to says "No steel case ammo" but the only ammo I've ever seen checked was rifle ammo, they don't want any steel jackets or projectiles. Only reason they wouldn't allow steel pistol cases would be wanting the brass to sell...
The near local WallyWorld had UMC 9mm in steel when I checked Saturday. I think it was 400-round boxes for $68. The 200-round boxes of Winchester brass were $48. Both were 115gr. I almost sprung for the steel but have never used it and didn't want to have 399 rounds left over if I had a problem with it.