That, sir, is the $64,000 question.
Find that out and you'll make many people happy!
Look here (and elsewhere) for information about Yugo 8mm builds, .308 bolts vs. 7.62x39 bolts, etc. and some people (myself being one) are of the opinion that they will handle moderate .308 pressures.
SAAMI recently altered their .308 pressure rating, so they began making .308 Saigas with 3 lugs vs. the standard 2-lug design. That's why I believe they can handle *moderate* pressures, at least by the new SAAMI standards. These standards are supposedly quite high, so they may very well handle *any* .308 pressures, but no one has been brave enough to try to destroy one yet.
Others have made different chamberings up to .308 pressures with no ill effect. Yet.
Most people are correctly choosing safety over anything else.