Just my two cents on the Detachable mags: everyone seems to have problems with the Yugos, but my old roomate bought a chinese with a fixed mag, bought a whole box of sks mags at a gunshow, various makes and sizes, and we shot the hell out of it, never had any problems with any of them, other than one of the 50 rounders not feeding the last couple rounds very well, but thats to be expected from any 50 round mag, it was mostly for looks, i think. (it did look impressive.) Too hard to load by hand too.
Like i said, the 20, 30, and 40 round mags worked fine, and we must have fired off thousand