If the steel is AR steel, even a FMJ/TMJ out of any pistol round should do little more than leave a mark on the paint. If it's doing anything other than that, it's not AR steel.
Out of a low velocity round like the .45, using even a FMJ round should be jsut fine, so long as the targets are properly set up and properly designed. If that's not the case, all bets are off.
The only reason people freak out about FMJ rounds is because they don't expand nearly to the degree that soft points or HP ammo does - on soft targets. You pop a good steel target with FMJ round out of a .45, and the round is going to deform just like any other round.
Gun ranges don't often allow them because their berms are not necessarily designed for the greater penetration out of rifles that a FMJ round displays versus a soft point or hollow point, and for the sheer fact that ricochets with a FMJ round will usually fly much futher and with more velocity after skipping off the ground than a SP or HP round will do. It's strictly a liability issue.
To the OP, if you can find some lead remanufactured ammo (or if you reload, roll your own with lead projos), you'll save yourself a lot of cash and meet all of the requirements for non FMJ ammo.