What,no comments? Maybe I can kick it along.
I first started shooting in my house when I was about 4. With a pop gun. It was murder on flies.
The first range I fired on was indoors. (and it was full of people.)
Since then there wasn't much reason to shoot indoors, but a few people I visited had indoor ranges in their house, mostly for .177 target air pistol practise.
As far as I know, Win. .22 Long Z's, the Z stands for Zimmer, which I think is German for "Room". IE. shoot in a room.
In my present house, the kids have left home, my wife works, the downstairs area lends its self to 13m. past a door, chain locked from the inside. The backstop is against the brick garage wall, and consists of a large sand bag.
I use a bench rest to test various types inc. CCI cb-Longs.
For standing offhand I use the pump up air rifle on only 2 pumps.
I've also used all plastic .38cal ammo powered only by a primer in a revolver. All good clean fun... for me and the dog.