I bought one of these from Palmetto state armory a few days ago. It fits in the magwell simular to the way the Lancer L5 or standard GI mag does with a slight amount of wobble but seems to be more rigid, less breakable in construction by sight. It loads/feeds really well, the follower is anti-tilt and slides really nice. The spring seems a bit stronger than the P-mag. Overall I still like my P-Mags better as they fit in the magwell really tight, no wobbles. Another new polymer mag came out by Tapco too, if it's as good as their AK mag that might also be one worth trying. http://www.palmettostatearmory.com/301.php "Tango Down ARC MagTango Down's ARC Mag takes full advantage of the latest polymers available from the aerospace industry- materials impervious to the effects of solvents & lubricants. After molding, they permanently bond the two sections together with advanced adhesives during manufacturing, so no disassembly is possible, or required. ARC Mag has a unique low-friction semi-floating follower that is slotted to allow for easy magazine cleaning. Just dunk the ARC Mag in hot soapy water, rinse and invert to drain. That’s hassle-free maintenance. ARC Mag also features a premium Chromium-Silicon spring that is heat treated stress relieved and Moly coated that is tested to 100,000 cycles. The patent pending two-piece modular construction allows Tango Down to create the ultimate magazine for many reasons. In addition to the proper magazine form, they were able to achieve maximum strength and integrity when the components are molded. Precision molding is achieved much easier on two small parts versus one large one. Modular construction makes perfect sense for the unprecedented strength- they eliminated the removable floor plate, so the magazine becomes a five-sided box. ARC Mag survives the impact that crushes metal magazines. Tango Down's design team created a magazine that could be handled by the operator in any condition- note the aggressive ridges front and rear. They allow a positive purchase when seating the ARC Mag. The deep waffle pattern on the magazine’s sides assist in rapid extraction from mag pouches. Every surface on the ARC Mag was given careful consideration to help out the operator."