^^^^^^^^^^^^^^^
It's all about courtesy. Unfortunately, we can rarely call it common courtesy.
Add common sense to that, on the part of the range owners. It used to be that the default standard was no magnums or big bore rifles.
But on the other side of the coin, in certain areas outdoor ranges have become fewer and far between as suburban sprawl shuts them down, so maybe it's more the case that range operators are aware of that and softened their stance with there being no alternatives available to many shooters these days?
In the location where I'm at, I moved to the far eastern section of the country in 1987. At that time the city of Brentwood was a rural farming community, within 5-8 years later... not anymore.
A tract development was constructed near The Brentwood Gun Club range which was out in the middle of freaking no where, surrounded by open farm land. The first time I drove out to find it I got lost.
As the tract development grew and got closer to the range, the home owners started complaining about the noise and risk of stray bullets. The range built a 20ft high U shaped backstop made from what looked to be railroad ties around the range... but the development eventually grew until it was right there on the opposite side of the backstop. They were ultimately successful in getting the range shut down.
Which is a supertanker load of crapola... the developers built and people bought with the full knowledge that the range was there... how could they not know?
And then the Johnny come lately jack wagons had the brass to complaint as if the range magically appeared during the night like a mushroom?
Yeah, It still steams me to think about even with it being well over 10 years ago since it's closure.
But as to the question of a 500 magnum (or any magnum) being appropriate at an indoor range... my question is what's the alternative then, to people that have them, if there's no other legal place to shoot them?
Prohibiting them feels like it would be the same as banning their sale... if you can't shoot it why buy it.