My Ruger SP101 357 magnum, and my Sig P250 in 357 sig. They are loud in the indoor range.
A guy next to me was shooting a Glock 20 with some handloads. That sucker was LOUD! It was actually distracting me while I was shooting. I finally leaned over while he was reloading and asked him what he was shooting over there.
Sig P220 Stainless Elite 10mm, GLOCKS- (19 Gen 4, 20SF, 21SF, 30SF, 42, 43), Beretta 21A Bobcat, Patriot Ordnance P415, Patriot Ordnance P308, Sig 556 SWAT Classic, Colt LE6920, Kel Tec KSG, 6.5X55 Swedish Mauser CG 1903 M96/38, 6.5X55 Swedish Mauser CG 1908 M96, Swiss K31 7.5X55, BNZ 42 K98, Ruger 10/22 50th anniversary design contest rifle, Tikka T3 CTR .308, Tikka T3 Lite .30-06, Winchester 1200