I think if you read closely the individual was referencing the FR7 rifles that were a modification of the 1893/1916 small ring rifles Not the large ring M43.

"OK, now we are to the meat and the purpose of this post! In the mid 50's, Spain is considering adopting the CETME rifle. To prepare the troops for a rifle that is so radically different from the Mauser design, Spain modified many 1893 and 1916 rifles to the FR7 design, as a training rifle. Recognizing the design and strength limitations of these actions, they also developed a reduced power cartridge, called the 7.62 CETME. This cartridge is externally identical to the 7.62 NATO, but with a considerably weaker powder charge (40,000 psi, within the design limitations of the 1893 and 1916 actions). They also converted the Model 1943 rifles to the FR8, this is safer due to the Mod. 98 design, assuming a good heat treat.

So now the real problem arises. Spain surplused these rifles out, and they hit the American market. They will fit 7.62 NATO or commercial .308! What a bonanza! A cheap rifle that will chamber cheap and readily available ammo!

CAUTION!!!!

These rifles are not safe, and are not designed for, 7.62 NATO or .308 commercial loadings! If you have one and want to shoot it (I would!) you must use handloads approximating 7.62 CETME loads. A good starting point is to use load data for .300 Savage or .303 British cartridges. There is a lot of misinformation on the net regarding the safety of these rifles, but when putting your face behind that receiver, and starting your trigger squeeze, THINK ABOUT WHAT YOU ARE DOING! A large and well known distributor is floating a lab report that says they are perfectly safe, but they will not take responsibility when that bolt ends up in your eye!"

Having dealt with the Spanish small ring action, I agree whole heartedly. Keep the chamber pressures to that of the 7mm Mauser.