The FN FAL was an upper/lower design that started development in the 1940s and the introduced in 1952. The Nazi StG 44 was introduced in 1943, an upper/lower design also.
The various gas designs are also old. The Automatgevär m/42 from Sweden was introduced in 1942 and has the same gas system as does the M16. So the way firearms operate is quite old technology.
Glock introduced polymer in the 1980’s, but an 80% receiver can be made of metal (probably the case for most).
So my question is the firearms law on the books is dated from 1968. So how are they finding anything new in the law that wasn’t there at the time the law was written? If there was completely new technology after 1968 another law would have to be passed by congress to address the issue.
The most common pistol 80% receivers are polymer. AR 80% lowers are slowly heading the same way.
The original FAL design was completely revised after the war - the original development ended up becoming the FN49, which does not have an upper receiver. Development was restarted and the FAL was announced in 1950.
Polymer was actually introduced in workable form in the late 70s. The Steyr AUG appeared in 77 and is largely polymer. You can see the predecessors of that in the Nylon 66 from 1959.
There is also the new radial-delayed blowback action invented and introduced by CMMG in 2017, which is all new and has no precedents.
https://www.youtube.com/watch?v=GJTQOhh7KX8
Further, there are almost-all-plastic firearms now, ones that can be 3D printed.
https://en.wikipedia.org/wiki/Liberator_(gun)
Assuming that Congress would pass and correct regulations if new technology had appeared is a laugh. 18 U.S.C. §336 makes it illegal to write a check or technically use a credit card for less than $1 - and they’ve never fixed that. The 1984 The Computer Fraud and Abuse Act is hopelessly outdated and even makes it illegal to access many public websites without a stupid legality dance:
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Under the CFAA, it’s illegal to “knowingly [access] a computer without authorization” and obtain information from a “protected computer.” Here’s the problem: The way you get authorization to access most web sites is to agree to a company’s terms of service (that check-box you click when you sign up for an account). The CFAA allows the feds to bring criminal charges against users who break companies’ terms of service, meaning that a person could face jail time, not simply a fine, for what’s essentially a civil disagreement. In other words, a user of the dating site eHarmony who lies about his or her marital status is technically breaking federal law, since its terms of service read:
“By requesting to use, registering to use, or using the Singles Service, you represent and warrant that you are not married. If you are separated, but not yet legally divorced, you may not request to use, register to use, or use the Singles Service…You will not provide inaccurate, misleading or false information to eHarmony or to any other user.”
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More here: https://www.motherjones.com/politics/2013/07/3-most-outdated-tech-laws/
It’s a leftist rag, but they’re not wrong about this.