this!
maybe, but you also have to concern yourself with a new barrel, all the work involved with the shorter round, ( remember, their 7.62 is NOT the same as ours- ie .308 vs .311) and basically re-doing the entire rifle; it's a full blown CUSTOM job- you'll need a spacer in the mag to take up that extra space;different mainspring, maybe a whole different gas system or different piston( lighter) different sights- and that's just off the top of my head