dsb01 You may have solved this or found the error I am seeing, but the immediate issue I can pick out is that you are comparing PET[-CF] against PETG[-CF?]. These are NOT the same thing, and NOT interchangeable for building safety critical items, such as your receiver components, and/or Super Safety selector cam. PET lacks a Glycol, which serves to change the chem makeup of the polymer significantly enough that you will see completely different properties of strength and capability. PETG is not super impact resistant (I made a magazine out of PETG-CF and the feed lips exploded into 7 diff pieces, when I gave a typical 'ensure the mag is fully seated' tap on the bottom, when I slid into the Mag well), and def not safe for things like this. That is why the PET-CF is priced so much expensively from the PETG-CF. I hope that this helps, if you haven't found what you are looking for, since asking this. Also, sorry if I am telling you things you have already determined. I would rather risk being the annoying guy that states the obvious vs saying nothing, and chancing someone suffering a catastrophic failure, and getting hurt because I opted to not bring something up.
