The booming is from handguns that are not twenty two.
The article made it sound like that was all you could shoot there.
That reminds me of one of the few times I used an indoor range here in Phx. I usually go to Ben Avery, but this time I was with a friend who had a membership at an indoor range.
Anyway, one of the guns we had brought was a .44 mag, so we doubled up on the hearing protection (both foamies and muffs and then went to our lane.
It turned out there was a woman in the lane next to us and evertime we’d light off that 44 she’d shriek BOOM! EEEK! BOOM! EEEK!
Me and friend got to laughing so hard we couldn’t shoot straight.