Probably one of the more overlooked pieces of the AR-15, when it comes time for cleaning and maintenance, is the humble mag. It is also one of the more vulnerable pieces of gear in regards to failure due to damage and dirt. Failure to feed and failure to eject a bolt that doesn’t lock to the rear after the final round, and a double feed can all be caused by a dirty or damaged AR-15 magazine. So the next time you find yourself running patches or a brush down your barrel, do yourself a solid and take a few minutes to check over your mags as well.
There really isn’t much to an AR-15 magazine, and cleaning it is a snap so there really isn’t an excuse not to. Besides, considering the failures a malfunctioning magazine can cause, it should be considered just as important as servicing your firearms.
Generally speaking, all magazines break down the same. Remove the floor plate, remove the spring and follower, done. Some manufacturers have a second plate in the bottom of the mag that interacts with a detent on the actual floor plate, and others have a block (round limiter), but we can account for these differences by renaming the parts:
Floor plate (keeps the internals from falling out).
Guts (everything in the mag)
The body (…well, the body…).
You are going to want to check that there are no cracks or pieces of material missing. If a floor plate fails, the guts and rounds end up at your feet. For polymer mags, you are also going to want to inspect the groves in the plate and ensure that the corresponding lands on the bottom of the magazine have enough overhang that there is secure contact.
Just give it a pass through with a damp hand towel. Think of it as a really big patch, and you are swabbing the mag. Excessive buildup of fouling gives small grains of dirt and sand a perfect place to imbed themselves; which can, in turn, bind up the follower. A bound follower will result in failure to feed. Next inspect it for damage. A cracked or misshapen magazine should be retired. Dents or dimples in the side walls can bind the follower; bent feed lips can cause double feeds or rub the carrier causing failure to extract.
Metallurgy has come a long way in regards to the durability and corrosion resistance of spring steel. While these advances have spawned terms like “maintenance free”, such is only the case in regards to the spring itself. The spring is part of a system, though, so leave the marketing ploys at the curb. The spring should also be wiped free of dirt or fouling that found its way into your AR15 magazine. Lubricant is generally not necessary, but a light coat will make clean up next go-around that much easier.
Excessive wear on the sides, front, or back of the follower can cause it to tilt while traveling up the mag and bind in place, once again causing failures to feed. A worn down rear can also cause the carrier to fail to lock to the rear after the final round. While all of these conditions are so rare that most never see them (or even know about them), they do happen. Particularly now that a lot more people are taking classes that emphasize speed in reloading. You end up dropping your magazine in the dirt and leaving it there until you finish your lane. Then you pick it up and load it right back up. All that dirt is like sandpaper between the follower and the body.
Once everything has been given a good once over, reassemble the magazine, load it up and empty it by hand. That was just to ensure that everything is moving smoothly. Now load it up with dummy rounds and cycle a few through your fire arm as a final functions check.
What only took a few more minutes on a day already dedicated to the range, could have just save your life. Now make AR-15 Magazine Maintenance a part of your ritual and keep on gunnin’.