Wizardofflights prints from a year and a half ago show the threads.
Serenity and I knew they were there.
The reason that the "Fan made" ones do not have threads is the fact that they are so small.
Pain in the butt.
I think that may be why Jango's gaunt darts don't. If they were made in a shop that is and not robbed from something the way Boba's were.
Now that we know that they are stainless, it could be easier to do. When you use a die on aluminum that small, it gaulds up and rips itself apart.