Hello and Welcome to the AR-15 Magazine Modification Page. Here you will find information and pictures of the process to modify normal AR-15 magazines to work in other rifles that are not chambered for the .223 or 5.56 Nato round. I can only cover conversions that I have done so please don't ask about other conversions not covered on this page. I will be happy to help if you have questions about my conversion process if I can. Just send me an e-mail with your questions and I'll try to assist.
First you need to know the difference between the most common followers. Below you will see some pictures of what can be commonly found in the
AR-15 magazine. Now don't get too hung up on the color of the follower. From my experience manufacturers change the color of their followers like
women change their minds. I suppose there is a reason for the color changes, but they all basically do the same thing no matter what the color is. The
biggest difference you can see is the design of the anti-tilt follower made by MagPul.
NOTE: I did not alter the feed lips on any of my magazine conversions. I did smooth the ends of the feed lips slightly, but I did not increase
the gap between them. My mags function perfectly in my rifle. You may need to widen the gap on your magazines if you find the bolt is not picking
up the cartridges cleanly.
Next I will cover what followers I used to do my conversions. Most magazine feed problems I have encountered were due to the crappy followers that come installed in aftermarket magazines. Aluminum mags are the worst in my opinion. Most of what I have seen lately come with a "green" Mil-Spec follower. While this may function most of the time with standard issue .223 rounds they are not very compatible with other cartridges. The biggest problem with the Mil-Spec follower is that it will allow the nose, (the bullet), to cant down upon cycling and get caught on the feed ramp of the barrel. Anti-tilt followers keep this from happening. MagPul makes some very affordable and reliable anti-tilt followers. I have not found anything better and if you read the reviews on most mail-order businesses you will find most agree with my assessment. Just type in" MagPul PMag Follower" and do a Google search and you will find where you can buy these. Generally they come in a pack of 3. The first picture below shows information on the followers that I am using during my conversions. Once you try these you will never go back to the old Mil-Spec follower.
Next I will show you a what a Generation 3, Magpul follower looks like when converted to be used with the .25 WSSM cartridge. This conversion is being made to a 20-round MagPul PMag. It is my understanding that the 30-round PMags are not as difficult to convert, (but I haven't done one yet so I can't really comment on it.)
As you can see from the pictures, there is quite a bit of material that needs to be removed from the follower to make it work with the 20-round PMag, but
it can be done. You will need to remove material off of both sides of the follower and both ends. I found this process very easily done with a Dremel tool
and both the small and large round sanding wheels. You will also need a small piece of fine-grit sandpaper to smooth out the edges.
Once you have made the alterations to make the follower fit into the magazine you will need to alter the "bump" on top of the follower. Here again
you will find a Dremel tool and sandpaper wheel to be invaluable. Once the "bump" has been reduced and hollowed use the fine-grit sandpaper to
smooth out the edges.
Once you have the follower done, then you will need to make a few mods to the magazine itself. Some mods shown may not be critical for it to function, but it will make the function more reliable and work smoother for automatic operation in the AR. The first pic shows the factory 20-round MagPul follower that came with the magazine. The second pic shows the difference between the factory magazine as received and the magazine after I made my alterations for the .25 WSSM. The third pic shows where I ground down the inside "lip" of the 20-round magazine. The fourth pic shows the font of the mag and how a loaded round will sit in the mag, ready to be used. The fifth pic shows the area that must be removed so the rounds will sit in the center of the follower. The sixth pic shows the rounds as they look while in the magazine. The last pic shows the small amount of relief that must be made to allow the PMag to lock into the rifle's Magazine well. Notice the difference between the factory magazine (one the left), and the the small amount of material removed on the modified mag (on the right).
Below you will find pics of a 20-round metal (aluminum or steel) AR-15 magazine that I converted for use in my .25 WSSM upper. The conversion process for metal mags is much less labor intensive than for the Pmags because the aftermarket MagPul followers are designed to be used in metal magazines. Really the only modification you need to make is to remove the "bump" and hollow it out so the round will sit in the middle of the follower instead of off to one side. I also ground down the front of the mag to keep the case mouth from catching on the magazine during cycling. The last pic shows that the magazine catch hole must be enlarged just slightly. Go slow with this step and check it in your upper so that you don't take too much out and make the magazine sloppy in the mag well. I have test fired these modified mags and they work 100%, which is much better than the factory mags that I bought with my upper. After replacing the followers in my Olympic magazines and making small mods to the front of the mag these worked excellent as well.
