It's not the same situation, but the approach to the cure may be.
Nobody changed the hardcore smoker's mind. People still smoke. What changed is enough people who previously had no opinion formed an opinion and peer pressure had changed how people smoke. Used to be you could light up pretty much anywhere - some people would be repulsed, but a lot of people weren't opinionated enough to say anything. Through the '70s and '80s that changed, and suddenly the crowd wasn't 10% smokers, 10% anti-smokers, and 80% dgaf, but 90% anti-smokers. Now you gotta light up somewhere else.
Non-gun-owners VASTLY outnumber gun owners. There are like 30% of households that have guns, so there is a clear majority a non-gun-owners. But, those stats are per-household, and there's a certainty that a large portion of households have a gun owner and some other people. The stats show 3% of the population own half the guns, so that really suggests at a small number of actual owners. Right now, you have a people who are pro-gun, and people who are anti-gun, but the vast majority of people don't have a strong opinion one way or another. When that fat middle section finds out a friend has a gun, they don't care. What will change that is when they do. When owning a gun becomes something you gotta hide instead of something you fight openly for, the tide will shift.
All the big shifts in behavior (if not thinking) come this way. The foundation or nature of the dying belief doesn't matter so much. Peer pressure is always the solution.
Is there a historical record of gun ownership? is there a way to know the historicity of handguns per capita?
acket.
We don't register firearms and the NRA doesn't allow us to use computers... there's no way to accurately calculate that data.
Units shipped by the manufacturers to dealers?
I mean, you guys invented the soundscan! you people tell me at halftime the attendance of all NFL games!!
acket.
Figuring that out before the National Instant Criminal Background Check System took effect in 1998 is difficult, and even those numbers probably understate the number of purchases somewhat (so long as state laws allow it, more than one firearm can be purchased per background check, IIRC). It gets even more difficult prior to the Gun Control Act of 1968, when direct mail ordering was prohibited, serial numbers were required, and import restrictions took effect.
So go back before 1968 in particular, you'd have to cobble together business records that still exist, and estimating production from known serial numbers. The estimates will get fairly wide for imports, especially since some of the super cheap handguns prior to that didn't have serial numbers, and there were huge quantities of surplus arms shipped into the country post-WW2 by various importers.
So in short, before 1998, you're probably getting rough estimates at best.
I'm sure like everything it's always going up. Guns have gotten relatively less expensive, there's more variety, and like drugs and Saabs they have transitioned from a specialized tool to collectibles and curiosities.
I wouldn't really say that they've gotten cheaper across the board, but they have become a lot more lethal and reliable for the same price due to advances in injection molded polymers, metallurgy, and CNC equipment becoming cheaper.
Back before the 1968 Gun Control Act, you could buy something like an RG-10 revolver for $20-25, while the modern cheap gun du jour, a Hi-Point, can be had for $150-200. However, the RG-10 was chambered in .22 Short, not a particularly lethal cartridge, while the Hi-Point is available in the common and much more effective defensive pistol cartridges of 9mm, .40 S&W, and .45 ACP.
I don't know if rifles were ever cheaper than they were post-WW2 when they'd be shipped back from Europe by the barrel. Of course, those were long, heavy bolt action rifles firing 6.5mm-8mm full power cartridges that were mostly used as cheap hunting rifles. AR-15s have become cheaper over time due to automation becoming cheaper, but AKM pattern rifles have actually become a little more expensive due to cheap post-USSR dissolution surplus drying up.
According this calculator, $20-25 in 1968 would now be worth about $140-180, so not actually that far off.