An update - I've created early designs with full theoretical functionality, including a short stroke system and a locking system. I need to refine many aspects and then fdm test parts as placeholders for the metal to stress the mechanical elements function.
I believe that any file release claiming to be "open" should provide the files in a way that allows anyone to easily edit the schematics without needing to modify (with difficulty) or manually reference the model.
Yeah that is a downside
Using major social platforms for 3D2A is not going to last, don't rely on them
GF has quite a lot more creep than CF in testing so that should be factored in
Any experience with PET-CF?
You could multi-material to cover the outside in them
QIDI seems to be better in terms of pricing.
I think expectations need to be maintained when making higher caliber weapons. I think what would count as "DIY'able" to me is for the gun to be made in Europe with no special equipment or custom parts, only with FDM, standard tools and common metal parts (except the barrel). Without welding is ideal but not necessarily a requirement.
Delayed blowback does not really solve the problem because it wouldn't work for stronger rounds (or it would likely be unsafe). For a piston system (for example) a steel block could be used, then one hole drilled that connects to the gas port hole and then one larger drilled hole containing the hammer system. The hammer used could be a common metal part that simply fits the diameter of the drilled section.
What about PAHT-CF? Seems underrated. Tensile properties look good.
You probably want a material with the least creep