Need detachable mag for yugo SKS

I finally took the new SKS to the range to test it out. Now I know some people swear by the original attached mag but I dont want to live with such a short mag capacity (5 I think it is, not sure). Anywho I bought a steel 30 round mag from a gun show and tried it out. And sure enough it didnt work well. The follower was getting stuck about 10 rounds down the mag. But mostly after the last round was fired the bolt grabbed the top of the follower and jammed it into the mag. So I pitched it in the trash. I fired some more rounds feeding them one at a time in the bore by hand. I looked at a plastic mag that seemed to be better but couldnt try it out. Does anybody know of a good mag that works with a yugo SKS?