I quite agree that context is always needed to evaluate things correctly.
I have a CETME rifle and so have done a little research on them, and from what I read I was under the impression that the driving force for the development of lower power CETME 7.62x51 ammunition was the introduction of early versions of the CETME auto loading rifle. As the Spanish did not yet have sufficient inventory to equip and train all of their troops they elected to rebarrel the Mausers they still had in inventory to the same caliber and issue them to auxiliaries.
I do realize that I can get a little lost when I go down one of these rabbit holes. That's why I reach out to folks like you and the others that were kind enough to respond to my post. Helps to keep from getting into too much trouble.
Just like when building a house you want to start with a good foundation, a good ROT to avoid trouble when building a rifle is to start with a good action.
But it's your $$, your build, so you should do it your way.
