John Sosta and the "Pro-Mag"

[MAGslinger]

Could someone please give me some info on this Mag. I'm going to do a story and youtube vid of it exclusively for automags.org I snagged this one off mcarterbrown.

[punkncat]

Search this forum. There is already a pretty informative thread about that particular (type of) mag.

here it is (http://www.automags.org/forums/showpost.php?p=2321347&postcount=12)