Well... for me it would be easier to list the ones less than 100 years old. A quick check and I'm finding that well over half my firearms are past the century mark age-wise. Here's a pair of my oldest Smiths, single actions. A 38 from around 1875, the 32 a decade later.
This pair of Stevens model 35 are my oldest non S&W. Its hard to date them because records were destroyed in a fire after WWI but I am sure by the barrel stampings that the bottom one is pre 1916, while the other may not make the 100 year mark.
I have a rack of old single shot rifles: rollers, trapdoor, Stevens of various models, a pair of 1885 Winchesters. All except a Stevens Model 34 favorite and 414 Armory are certainly 100+ years.
Half of my Model 94 Winchesters are century guns. Plus a Marlin 93. I'm down to three bolt action rifles and two of them are older military sporters that still see action every fall.
A couple of my newest rifles are reproductions of older models: have a pair of Sharps rifles and a model 92 Rossi. That last one is probably the youngest gun in my stable.
Cartridge wise, I don't have a single rifle round that wasn't born less than 100 years ago. And in the handgun field, only my .357 and 41 rem mag are "new".
Are you guys seeing a pattern here? 😁
I guess my gun room is a museum of sorts. I even have a pile of old ideal reloading tools to keep them company.
All this old stuff keeps me young.
"Timetripper" John