The general feeling is that FFL dealers can buy them across state lines. I believe Benchmade only sent repaired ones back to FFL dealers. There are many dealers that will send them to retailers and individuals over state lines, but that does NOT make it legal.
Killgar I believe the 2005 case is the one I was thinking of.
It's my understanding that the Federal Switchblade Act provides only two legal ways to ship switchblades across state lines-1. "pursuant to contract with the Armed Forces" (Section 1244 part 2), and 2."The Armed Forces or any member or employee thereof acting in performance of his duty" (Section 1244 part 3), in other words, military personnel shipping switchblades to other military personnel/units after the knives have already been purchased pursuant to official contract. The Act makes no reference to vendors shipping switchblades across state lines to anyone else, including civilian FFL holders.
There is debate regarding whether or not it's legal to use "common carriers" to ship switchblades across state lines (Section 1244 part 1). AKTI says "common carriers" are exempt, but Kniferights doesn't. Kniferights appears to say that the "common carrier" exception only provides the carriers with legal protection if they transport switchblades across state lines, with no mention of immunity for the sender or recipient. But frankly, I think the issue is moot at the point, particularly if the Feds are not interested in enforcing The Act.
Lots of people in this country, and lots of businesses are violating the Switchblade Act. But you are correct, the fact that a law is not being enforced is not the same as something being legal. But if the law is not being enforced, there's a lot less reason to worry about it.
Like I mentioned, there are many online knife retailers, both big and small, who openly advertise switchblades for sale, and ship them across state lines. And I know from personal experience that some of them use the USPS to ship them. I would imagine that big online knife retailers have a lawyer, if not a law firm on retainer to handle all of the many legal issues that come with owning and operating a business, not the least of which are liability concerns, particularly important for a company that sells knives and weapons. And I also imagine that those companies, and their lawyers, have carefully and thoroughly researched the matter, likely even consulting the DOJ.
I doubt that any of the online retailers who openly advertise, sell, and ship switchblades across state lines to the public would risk Federal prosecution, lawyer fees, crippling fines, and seizure of assets, just to sell Joe Average a switchblade, if they thought there was the slightest chance of being prosecuted. Especially when you consider how easy it would be for the Feds to make a slam-dunk case. So my guess is, they have inside information and know the Feds aren't enforcing The Act.
I would also point out that MANY of the switchblades being openly sold by online vendors, both big and small, are imported into the US from other countries. Another violation of the Act. And I don't mean a few switchblades, I mean LOTS of switchblades (mostly from China). But apparently the vendors aren't worried about that either.
I think the fact that so many online retailers are openly selling imported switchblades to the public says a lot about the current status of the Federal Switchblade act.