I wouldn't be surprised if the myths surrounding steel ammo all originated with gun ranges trying to squeeze another buck out of their customers. That's certainly where I hear them spouted more often than not. It destroys our backstops, we have to ban everything magnetic to prevent armor piercing ammo from sneaking in, it'll break your gun and cause it to spontaneously combust... Pure BS. First of all, legal steel core ammo isn't going to hurt their backstops, assuming their backstops are sufficient in the first place. US law requires that steel core ammo be a mild steel, and there are actually solid copper and brass bullets on the market that are harder than your average combloc ammo, and will readily pierce higher grades of steel, especially considering they're more common in high end big game cartridges.
It's also BS that they have to ban all magnetic ammo to prevent armor piercing rounds from sneaking through. Anything that's tungsten is non magnetic, and if there's any bullet that's going to damage their backstop that's it.
As for being a fire hazard, that's a new one. Copper bullets will spark when they hit something hard, but I've
never heard of a fire being started by a bullet, any bullet, unless it was incendiary, which a magnet will not detect BTW. Plus I've never had my ammo inspected for tracers, or been told in any range, indoor or out, that tracers were banned. If fire is an actual concern for them then you would think they would be a bit more proactive about banning tracers.
And I don't care if it's indoor or out, if they're worried about fire then they need to clean the danged backstop!
My local indoor range recently banned steel cases. I talked to the owner about it and he admitted that it wasn't so much about steel core ammo problems on his back stop. They sort, clean and sell their range brass themselves and got sick of picking all of the steel cases out.
You should ask him if he's ever heard of a magnet.
Seriously, you think he would be more concerned with aluminum cased ammunition, which requires you pick it out by hand. And yet I've never been to a range where aluminum cased ammo was banned. In my experience if it passes the magnet test then it's always GTG. Funny how they know that steel is magnetic when inspecting your ammo, yet they suddenly forget this fact when sorting their brass. Of course I'm sure that they're plotting some excuse to ban aluminum as well.