Just got back from the range this morning, went out to try my old sks with a duckbill mag a friend gave me. Was the second time i used it and as expected the first time was a stoppage festivale. When i got home the last time, i started taking some measurements on both the original mag and the detachable one and found that the lips on the detach were to high. So after a little hammering session i went out again today to try it and after 300 rounds with no stoppage what so ever i concluded my morning shooting trip. So now i've got a nice mean looking SKS! 