I've never seen a ban on steel cases around here. However, they do ask you to not shoot steel jacketed ammo due to the danger of starting a brush fire. We are under a red flag warning today as we have low humidity with some winds. I hear plenty of people shooting on BLM land everyday behind the house.
There is a difference (often misunderstood) in the banning of steel cased cartridges vs. steel jacketed bullets. Some ranges collect and sell their spent brass to reloaders and/or recyclers. It takes a lot of effort to separate the steel and aluminum cases from the brass, because the recyclers buy it by the pound and will monetarily penalize the range if they inadvertently mix steel/aluminum in with the brass. Hence, many ranges will ban steel altogether but will allow aluminum because it just isn't as prevalent. Some ranges ban both (steel and aluminum) to make the recycling easier.
Most all indoor ranges ban steel jacked bullets. Most eastern block surplus ammo is made from lead bullets that have a thin steel outer jacket covered by a wash of zinc or copper. The thin steel jacket is banned mostly due to the fact that it often sparks when it hits a solid -- such as rocks or steel barriers. In an indoor range that spark can (under certain circumstances) cause unburned powder in the air to ignite. It's mostly a scenario at ranges that don't have proper ventilation, but many ranges can't get insurance coverage (or are charged a premium) if even that remote possibility exists. Hence no steel jacketed ammo at most indoor ranges.
At outdoor ranges in most of the country steel jacketed bullets are OK. In brushfire country in the western states though, it's often prohibited. At the indoor ranges where I shoot, the range officers will check your steel cased ammo bullet tip with a magnet and certify it as acceptable. Also, there are many variations. Some brass cased ammo has a steel jacket (Stryker 55g FMJ 5.56x45 brass cased ammo has a steel jacket for instance), while some steel cased ammo is now produced as being "Range Friendly" -- meaning it has no steel bullet jacket, but just a plain copper jacket over the lead bullet (i.e. non-magnetic).