You call these project[s], which I think is very accurate for the higher power cartridges. You sound like you've seen a lot of the videos of 3D printed firearms, and from what I can tell they cluster around 9mm and 5.56. There's probably multiple reasons for that, one of which is that those round sizes are more widely available and cheaper, while another is that it is going to be easier to do than something with higher power. So to maybe simplify my point, the technical challenges and inherent safety issues on 7.62 are higher. Thus, projects they shall remain.