From 10 to 30 with a left over p-mag spring for endomag'ers - Hexmag Series 2 AR-15 5.56x45 10 Rounds Rifle Magazine

Yes they're blocked at 10 rounds and yes they can be converted to 30 in a few steps. Take a punch or a screw driver and a hammer, punch out the small circular hold pin on the bottom, pull out the inner parts with the limiter spring and replace the spring with a full function 30 round spring. You still need to use the original top and bottom parts from the Hexmag. For all you Endomag people converting 556/223 P-mags to 9ers, save the unit you remove from the P-mag, the spring works perfect for turning this 10 rounder into a 30 rounder. Take the Hexmag feeder top and base plate bottom off the limiter spring set up and replace with the left over spring from the P-mag/Endomag conversion. I had no idea what I was doing and it took less than 10 minutes.