STANAG magazines were first developed for the Armalite AR-15, which was first released over 50 years ago. Over the course of time, there've been a number of milestones in development. This section of Gunwiki is dedicated to analysis of the differences between several of the STANAG magazines presently on the market. The emphasis of this article is, as in the picture above, on the differences between the parts of the various magazines and the intercompatibility thereof. Note that many of these magazines have different solutions to the problem of "tilt". Tilt is the condition where it's possible to press down on the front or the back of a follower and tilt it within the magazine body. Modern anti-tilt followers are extremely resistant to tilt, and will refuse to substantially deviate from a horizontal position.
The black follower in these pictures is the original follower used in M-16 magazines. The green follower is the anti-tilt follower designed later on, in response to some of the reliability concerns raised by soldiers in the Vietnam war. Note the long leg towards the rear of the green follower - this enhanced stability and prevented the followers from wedging themselves angled backwards in the magazine. However, it's still possible to "nose down" rounds in the magazine by pressing down incorrectly.
Underside view. Note that from this angle, the two followers are nearly identical.
Another underside view. Note the hole in the center leg of the green follower. Although it's difficult to see, the black follower has a similar hole in its center leg. These holes are intended for the magazine spring to be threaded through.
One place where magazines tend to diverge from the USGI standard is in floorplates. Each of the floorplates below belongs to a STANAG magazine, and the only ones which can interchange are the USGI and Promag floorplates. It is recommended that you click this picture for details, paying particular attention to the retention clips on the USGI floorplate at top right.
From the side, it's apparent that the Magpul follower is thicker than its USGI counterpart. The front of the follower is thick, with molded plastic supports going out that hug the ribs built into the sides of USGI magazines. This helps substantially with the resistance to tilt, and the fuller, wider front and rear sections improve matters as well.
Note the provisions for attaching the spring to the follower. In the green follower, there's a hole so that you can thread the spring through like a needle. In the C-Products follower, there's a clip which the wire snaps into. This does make installing and removing the springs considerably easier. At any rate, in this picture one can see that while the protrusion on the green follower which grabs the rear rib of the USGI magazine is relatively short, the anti-tilt follower uses nearly twice as long of a rib to avoid tilting. Additionally, the surface area to either side of the rib is in contact with the follower.
The first thing which should stand out about these followers, to the casual observer, is how very similar they are. To save you some looking, the orange ones are for aluminum mag bodies and the black ones are for stainless steel. If you look closely, you can see that the Aluminum followers have "AL" molded into the follower and "SS" on the stainless steel followers. The stainless steel followers will NOT work in aluminum magazines. They do not fit. They will however interchange just fine with the followers on the HK high-performance magazines.
-- SeanNewton - 09 Jun 2011