Honest, why the **** does someone bring a shotgun or a 300win mag to an indoor range? what fun are either there?
Agreed, I can't see a long range rifle inside unless it's to get it on-paper or working on function.
Shotguns on an indoor range work pretty well though. You always (?) have to use slugs, and shotguns can be fun to shoot at 20-30 yards. I bring my HD shotgun to indoor ranges a bunch, and my S12 has made it to indoor ranges more than a few times. Those are great range toys, if nothing else.
That being said, if I bring a shotgun I always bring something else to shoot in case the range is full or has new shooters on it. Some ranges limit long guns to certain sections as well, which makes life easier. Even then, if I see someone startle or look like it's a problem for them, I'll pack it up and shoot something else.
The real issue here is basic consideration for your fellow shooters.