Replacement Magazine for the Stevens M416 .22 Target Rifle

Has anyone purchased a replacement magazine from Numrich for the M416 Steven military style target rifle in .22 cal? I ordered one and when received there was a note attached saying it was a "newly made" in China magazine for the M416 Stevens and another gun and "may have to be fitted". It would not even fit in the gun. My next question is, where you able to make the Chinese magazine fit and function/feed properly? Next question, does anyone have an original magazine they will sell me? My email is: garnettstancil@hotmail.com