My research this afternoon has shown that the CETME round was only intended for an early version of the CETME rifle due to heavy recoil and control issues on automatic fire.
The NATO round was designed on the weakest rifle/action in the NATO alliance and that would be the Spanish Mausers which were still in use and converted to the NATO round so even the FR-7's "should" safely be able to handle it although it is right at the edge.
Nearly all sources say the 308 round should never be fired in an FR-7, some also say the NATO round should not be used in them unless it is a reduced loading which is supposed to be available.
Other sources say that the Spanish NATO loads are heavier than the GermanNATO rounds and so standard NATO rounds should be fine with no issues.
It's all pretty confusing
Most do seem to agree that there should be no issues firing 308 rounds through an FR-8. As the NATO rounds are cheaper that the 308 rounds, I'll probably not use the 308's in any case.
This rifle is out of my usual area of collecting so I went into the deal without much research or knowledge. I had an idea of what they were going for and based on that what I was willing to pay with that in mind. Seller's bottom line price was one I couldn't pass up, $200.
Patrick,
From what I can gather, the barrels are new, not rechambered 8mm barrels and they are supposed to be NATO standard.
Your point on the sammi vs mil spec was mentioned on one site but your explanation is a whole lot clearer.