Forty years ago Viet Cong blacksmiths using tin snips and sheet metal were turning out 30 round magazines for captured M-16s.
Do these idiots really think a person with modern hand equipment cannot turn out a workable one in their garage?
Make (or print) Your Own AR-15 Magazines
http://gunwatch.blogspot.com/2012/12/make-or-print-your-own-ar-15-magazines.html
We need to keep spreading that information.