City born and bred 550 miles south of my present AO so my firearms were all on loan from my various friends. Mom and Dad never could figure out why their kids had such an interest in firearms but we all did, some of us more than others.
I remember .22s, a 16 gauge, and a flintlock. In the 60s.
Earlier? We had just finished kicking the asses of the nazis and the Japanese so many cartridges used during the war would have been popular, .30/06, .38, .45ACP. Of course there were war souvenirs also so I would imagine the various axis cartridges too, but I remember mostly .303 British for foreign cartridges. Was .30 Carbine popular? It would be my guess, but that’s just speculation.
Handguns? LEOs used mostly revolvers in .38/.357. Frankly, even in the '70s there wasn’t a huge choice as there is today. In the early 70s I was one of the few LEOs who carried a semi-auto and it was a Browning P35 aka Hi-Power. I remember seeing SIGs in the gun case at the LGS and I only remember it because of the sheet metal design. Even into the 80s I was one of the few with a self-loader on my hip at least locally. At one point I was called in to see the chief and he questioned why I carried it cocked and locked. But it was my off duty gun so he could take a hike. On duty, you guessed it, a .357 wheelgun. At some point in the 80s I swapped the Browning for a 1911 for off duty carry and semi-autos were starting to gain traction. I don’t remember any compact 1911s a 4" was the smallest and when I carried that it was a 5" 1911 and I tolerated the weight and mass. But a handgun should be comforting if not comfortable.
My childhood friends father was a deer hunter and he used a .270 bolt gun. That I thought was very interesting. Back then I would pore over outdoor magazines and ballistics charts to figure out “the best”. What did I know? I was a kid. But I had definite preference in bolt guns and they always had classic lines of walnut and blued steel. Weatherbys? Their looks grew on me eventually, and I liked the action even if I couldn’t see or fondle one. But even back then I questioned magnums and the shoulder that had to handle them. Then my brother came home from school in Utah in the late '60s and he brought a .308 (.300?) Norma Mag. That thing kicked worse than a mule and I decided that when I finally was able to buy rifles something like that cartridge wasn’t on my wish list. I have never bought a big .30. I remember that cartridge taking 70ish grains of powder, more than I ever want to burn in a cartridge.
Something I thought was amazing was a cartridge that was maybe earlier than the date range specified. In the late 1800s and into the early1900s the .32/20 was popular. I acquired a barrel for a Contender in a purchase of everything Contender that a friend owned. I wondered what I was going to do with it. Then I started to do research into it. Way back then it was quite the cartridge and was highly thought of for deer and bear. Even more startling is the load used back then. I seem to remember black powder and a 90gr lead bullet at subsonic velocity. My barrel it turned out was in .308 not the original .312 diameter, for use with commonly found modern bullets and for use in metallic silhouette. Not one to just accept things I decided to hot rod the cartridge to see what it would do in a modern action and modern steel since the action and metallurgy is why it was so sedate back in the day. I got it up to near 2000fps with a 110 grain bullet out of a 10" barrel and even that performance was questionable for deer today among the experts. That put more of an exclamation mark after the loads used way back when. FWIW, while the .32/20 brass may be thin the performance I get from it with my hot but safe loads are much like what can be gotten with 300BLK. FWIW#2, I would use the 300BLK for deer, and I would definitely use the .32/20. The key would be, as it was 100+ years ago, not shooting at the deer, but pick ones shot and shoot at a spot on the deer to make the shot good. That’s what I’ve always done anyway.
edit#2: One thing I remember seeing in the various adds for surplus ammo back then were the warnings for corrosive primers. Not sure of the years, but that had to be in the 60s. Sometimes surplus ammo is found today and the primers were all corrosive. People had to be warned because the civilian market was using non-corrosive back then. I have no idea what year they swapped from corrosive to non-corrosive.