I have both,...The S.A. mags seem to be of the same material...hold a minute ill go measure....yeah both are made of .046"-.047" steel,same followers and baseplates...the only difference i can see is that the IMI's are welded along the back using a folded seem and the S.A.'s are flush welded along the front..And the IMI's have a star of david(of course)...both those and the other "contract" mags work fine in my AR...The best deal i found right now is CDNN is selling 10,25 rounders "used" for 99.00$...Its not on their website so youll have to call them..I got 10 myself and they came quickly and were in good shape,Came with 5 IMI's 4 "unknown" contract and 1 "unknown" with the numbers on the back seem.....Then i sent them to this guy [email]
[email protected][/email] hellava nice guy and he cut them for me for 6$ a piece + 6$ shipping for the whole lot...that make them 16$ mags..Not bad.........hope this helps........UNDERDOG
[url]http://www.uzitalk.com/forums/showthread.php?s=dd5965d0fcd16e3b708019adf345acc6&threadid=567&perpage=15&pagenumber=1[/url]
this link may be of help to you also....
edited to add link