Feed lips position the top feeding round relative to the interior vertical front wall of the magazine and the barrel throat(chamber). Typically, in existing magazines. the round is positioned too low and the bullet nose nicks the magazine on the way out. Also, this low feeding position can cause feed ramp jams.

Our CobraMag solves these problems by positioning the top feeding round higher and chamfering the top front inside of the magazine. Another issue is the internal tube volume. Currently,  this varies from manufacturer to manufacturer and part to part   within the same manufacturer. You never know when you buy a     30 round mag if it will hold 29, 30, or 31 rounds because of this      variation in internal tube volume.

We qualify the internal tube volume                                                        of  our product so  that  it  holds  the  specified   numbers  of  rounds.   Our                                                         CobraMags    hold    exactly     the  number of rounds we say they will - no                                                         more and no less. Our CobraMag follower stop design along with qualified                                                         tube volume means the spring is never compressed to coil-bind (solid stack).                                                     The  longevity  of our spring is enhanced because it is never brought to full                                                       compression. Another benefit of our design  is  that  since  the spring never                                                        goes  to full    compression. The   top   feeding   round   of   a  fully  loaded                                                        magazine will strip from an open bolt easier  than a  30rd  magazine  where                                                       the spring approaches coil bind. Also, by design, our CobraMag has enough                                                        uplift on  the  follower to dependably lock the bolt back when  shooting dry.                                                     This sufficient uplift also prevents bolt  over feeding failures where  the bolt                                                      closes w/out stripping.

Our special chrome silicon spring is made from slightly larger diameter wire. Our testing showed this to be a superior spring over any of the available examples. We test load every magazine we manufacture. We load them to full capacity and hand strip every round to ensure that loading and unloading are completely smooth. We also live fire test and bench feed selected production magazines. We CNC machine our lower box, the spring plate with the follower stop column, and a removable floor plate to guarantee dimensional stability.
We think everyone should consider having a few of these quality magazines in their collection.