www.automags.org dude.
Mags might not be mainstream, but they are still very much alive.
I myself shoot an E-mag
I believe what you saw in the movie was tom kaye an an X-mag...
www.TheMagSmith.com
www.Tunamart.com
www.Airgun.com
www.whitewolfairsmithing.com
www.TheAlphaMag.com
These should help you out as well.