In general I’m a History buff, primarily military history which is where some of the most sentient advancements in manufacturing, firearms and medicine have occurred. The examples are too numerous to cite but are easily found. In general I think the point of highest firearms development began in the 1950’s, but more importantly was the improvements in cartridge component technology. As an example the venerable 30-06 was essentially replaced by the .308 (7.62X51) when required to perform at the same level (bullet weight and velocity) with a much smaller cartridge due to better powder options. Back in the 40’s if you reloaded you had mebby a dozen choices of powder to reload with. Now you have a dozen choices per cartridge CLASS. Primers the same.
Probably the most unrecognized “explosion” of gun advancement began to occur in the beginnings of 1994 prior to the “Assault Weapons Ban” and exploded immediately there after. In 1994 the U.S. Army and U.S. Marine Corps rifle teams went to the M-16A2. After surviving the Gulf War I was less than impressed with the attributes of a rifle that “Shat where it Et” but I could and had to learn to make it run but I still to this day refer to it as a “Rat Gun” out of deference to my beloved M-1A (M-14). On to my point.
The only reason I ever wanted to shake Bill Clinton’s hand and thank him was for signing the Sept 13, 1994 Assault Weapons Ban. Yes I just said that out loud. If you can find a copy of Shotgun News From 1993 there were Exactly 4 types of AR-15’s you could buy, AR-15A1, AR-15A2, “Commando” Carbine and mebby an XM-177 look alike and damn few “custom parts”. There were no picatinny rails, no flat tops, no gas blocks and free float tubes were competition “bloop tubes”. Ambidextrous charging handles or safeties or mag buttons, didn’t exist. In the 10 years of the Assault Weapons Ban the AR-15 platform became “Lego’s for Big Kids” and it hasn’t slowed down a twitch since. The M-16A2 I carried in 1990 was a whole lot different than the MK-18 or M-4 that I carried in Iraq and Afghanistan.