First of all congrats on the class 4, you will love the machine.
For the thread I would go with a bonded nylon or polyester, bonded nylon holds up well and alot of holster makers use it and it serves them well. Polyester has a higher resistance to abrasion and UV light and works well for items that will be used outdoors or exposed to prolonged periods of sunlight.
As far as weight of the thread your cobra will handle anything between 69-415 thread. Hope that helps answer your question.
Good luck and God Bless
Circle T
Guess I ended up with a bad one then, it bite me in the hind end on a custom pancake style with rattle snake inlay and a bunch of gun show avenger style holsters, lesson learned, now I check all my mold guns against manufacturers specs.
circlet
I would steer clear of the glock 17 version, the one I got isn't even close to the right size(width,length,height), the other versions that have already been named are accurate in dimensions.
Circle T
I had the folks at Texas Custom Dies make several dies with very difficult lines and they turned out spot on, great people to deal with and excellent craftsmanship.
I'm located in the same city and have that gun if he wants to drop by the shop, have him shoot me an email if interested. thanks
circletleatherworks@gmail.com