Gun Gear

Magazine Maintenance for the AR-15

Older model Colt AR-15 magazine circa 1960

The magazine is a part of the rifle, and it’s a moving part. The magazine feeds the daggone thing its rounds so it can fire its bullets. That’s how important the magazine is.

Four magazine followers Magpul, “green,” ancient Colt metal, newer Colt plastic
This is a follower. A whole line of them. It follows the rounds up from the magazine. The guide ridge is there to orient the cartridges so they “double-stack” correctly. The real improvements have come in changes to the front and rear guides or skirts. The old-style (Colt original, and similar) had virtually no support inside the box at the bullet end. The newer designs, like the Magpul, make it just about impossible for the follower not to sit correctly throughout its travel. This follower goes in all my magazines now, except for the old ones that already work.
[left to right]: Magpul, “green,” ancient Colt metal, newer Colt plastic
I get a lot of correspondence from folks complaining about magazine problems. I never liked the answer I gave them, and that’s led to this article. “Well, I use old aluminum magazines with metal followers and never have any problems…” I have been shooting off of the same Kroger-sack-full of Vietnam-era Colt-brand mags I bought in 1977 for $2 apiece. They all work.

Well, I finally got some new magazines! And then I had to fix them. So, now I have some answers.

There are four pieces/parts to a box magazine: the follower, which is the tray that lifts the cartridges into position; the spring, which powers the follower; the base plate, which secures the spring, and the box.

If you take your finger, or the eraser-end of a pencil, and push nilly-willy around on a follower, you sometimes can make either end stick down. This can also happen when the rounds are pushed up in operation. When you can’t make a follower stick from pushing on the front or rear, the magazine should function. The newer follower designs were drawn up to help that happen, when they are correctly oriented atop the spring.

When an AR-15 magazine malfunctions, it’s usually because the follower didn’t behave correctly, and the nose of the round stuck down and then stuck in on the front inside wall of the box. If the follower sticks down at the back end, the bolt rides over the waiting round because it can’t catch the cartridge base. The reasons followers don’t behave usually come from their orientation in the magazine.

Older model Colt AR-15 magazine circa 1960
It’s skin deep. Here’s one of 8 I take to Camp Perry. It’s an old Colt-brand made late-‘60s. Internally it should now be inferior to new ones, but it doesn’t work that way, and that’s because this one works. Off as it may sound, the aluminum GI mags are usually way on better than commercial steel magazines. If you see one that’s blotchy gold or silver that’s just the finish worn down to the anodizing. Don’t pay collector prices for Colt, though. Adventureline and Simmonds are others from that era that is very good.
The deal behind the “green” follower the armed forces went to was to solve a common problem of failures to feed the last 2 rounds from some 30-round magazines. The change was to add a skirt to the front and extra length to the skirt at the rear to help stop the follower from tilting. These skirts ride against the inside front and rear box walls. This follower design is better. Get them by the dozen for low cost.

I say, however, that there are fewer follower problems and more spring problems. A box magazine is spring-driven, and there are differences in springs. Chrome-silicon (CS) springs, when exploited to its capacity by the spring maker, is always better than music wire. CS magazine springs put a more consistent, constant load on the follower and, this is big, just don’t change. They can be left sitting compressed without getting “soft.” This is a huge concern and potentially disastrous circumstance for a tactical pro. If you want to check a spring for adequate load, put two rounds in the magazine and push them down about 1/8 inch. They should spring fully and instantly back up. If they don’t, the spring is sacked. Replace it.

The correct orientation for the follower atop the spring (neither installed in the box) is with the bullet-end sitting a little higher than the back end. Dead level is good; a little nose up is a little better. If you work with enough different springs, you’ll notice that not all springs will do this. You have to help.

Pliers are the tool and, again, the idea is to get the follower sitting just a little nose-up. Tweaking on the topmost coil does that. If the follower is nose-down when it’s installed onto the spring, when it gets back into the box and buttoned up, that orientation can return. Even if the spring is crammed in there and it seems that there’s plenty of pressure against the follower to keep it up and sitting level against its stops, when the rounds are dealt in and the follower goes down, the shift or tilt can happen.

There’s more to say, but another time. Until then, take care of magazines. Clean them periodically (at least once a year). Lube with dry lube if at all. I don’t. Oil traps grit.

How many magazines do have in need of repair? Do you have a magazine maintenance tip? Share your answers in the comment section.


Glen Zediker has worked professionally with some of the greatest shooters on the planet, as well as leading industry “insider” rifle builders, manufacturers, and proven authorities on gunsmithing, barrelmaking, parts design and manufacture, and handloading. And he does pretty well on his own: Glen is a card-carrying NRA High Master and earned that classification in NRA High Power Rifle using an AR-15 Service Rifle.

The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (21)

  1. best aluminum mags are the original 20 round vietnam war aluminum mags. they are straight not curved. you do not have to replace their followers because they only go straight up no pressure on a curve like the 30 rounders.replaced all of my 30 round followers with magpul followers. i think they are the best ones out there.

  2. Of all the AK magazine springs I have pulled and checked (new and used) the length has varied only about one coil height. I don’t load mine to full capacity to keep the first bullet from being thrown to high, which is the only problem I have seen from a good metal mag.

  3. AK metal magazines are worth tuning up, I buy six at a time of a type, disassemble them and match the followers to the can they fit best. Smallest follower to smallest can thru largest follower to largest can. This gives me the best results outside of factory go/no-go gauges.

  4. As a gunsmith, I have found certain caliber magazines are more troublesome than others. The most touchy, in that just minor adjustments of the magazine lips, can make a very big difference in the way they feed are .45 ACP, and they seem to vary more than any other caliber in the shape of the follower and the quality of their springs. The most troublesome as they arrive from the factory are .22 LR magazines. There are specific requirements as to the feed lips in .22 LR magazines, and they differ from the typical center fire magazines. More fresh from the factory .22 magazines need some adjustments before they are reliable than one would expect.

    1. Gary is there any way to repair a magazine i have some for a Winchester
      model 100 (.308) the spring is not strong enough to push the shell up it hangs? Please let me know I would love to be able to use those magazines
      give me 4 more rounds which may not be much to others but it does to me. Also I do use the gun it will shoot a 1′” group at 100 yards using 165g Failsafe bullets. That would be a really good gun to start making again with a good barrel and especially in the new 338 Federal and the old reliable 308 and even the 300 WSM. Please help me out. Thanks DT in ETN

  5. I had some old mags for my HK91 that would not feed the last three rounds. The fix was to take out the springs, stretch them, and put them back in.

  6. talk about multiple answers to the same question, I have to ask again. is it wise to leave the ammo in a magazine with the spring compressed or take it out when storing them?

    1. I would suggest that you store them full only for about a week at a time and then switch out to another magazine if you want one or more loaded for emergency purposes. A spring is just a spring and if you keep it compressed long enough I am sure it will loose some of its pressure as it will probably permanently bend the area where the spring folds and flatten it out eventually.
      The reason I say this is when I have had magazines with overly tight springs that do not allow you to fill them completely I usually go through a process of prolonged compression until I can get the extra round in and then keep them in that state until I can load all rounds in a normal fashion.
      In order to do that the spring must have stayed in that new state of compression. Just one opinion that should answer your question.

    2. Wrong. Do some reading on that there buddy. Chrome silicon springs are resilient. I’ve had several mags of both USGI (D&H and Okay) and Pmags loaded for years. In the most extreme case, 4 years….when I finally took them out of storage and ran them at the range, they still functioned perfectly. I also have friends and acquaintances who’ve done the same, with the same results. Even on Magpuls webpage they state you can leave them loaded for extended periods of time… what wears a spring out is flexing it over and over (compressing it, decompressing it etc). Not simply keeping it compressed for a long period. To the OP who asked the question – if you’re talking ar15 mags, and they’re 17-7ph springs, you can leave them loaded for a LONG time.

    3. So are you suggesting everyone has chrome silicon springs and everyone should follow only your advice “buddy”? I was speaking from my experience with the magazines I own which are probably the same ones many other people own. Now if you don’t like that I guess its just too bad now isn’t it.

    4. Yes, they’re firearm magazine springs. They make them well. Do me a favor, take the spring out of your oldest magazine, put it next to the magazine box…. about twice as long right? So by your logic, the spring should be the same size/length as the magazine becAuse it’s been in there, compressed for so long….. hmmmm but it’s notttt… ??? Whew, baffling. It’s not rocket surgery ma’am.

    5. So now you are going to tell me that my own experience with dozens of magazines is irrelevant and that what I have witnessed has been a hallucination. Please show me the scientific evidence that proves yours and only your experience is correct. You are definitely one of the folks who feels he has to have the last word so guess what. You will receive no more rebuttals from me because I don’t engage people like yourself beyond one or two times. Take a hike.

    6. How long will you be storing it?

      It’s the repeated flexing of the metal that eventually causes it to fail, and because of that frequently loading and unloading the magazine will hurt the life of the spring more than just leaving it loaded.

      It’s one thing if you don’t plan to touch the magazine for months at a time, but if you’re just going to load it up again in a few days it’s better to leave it loaded.

  7. So I was always taught to NEVER fully load a mag. I was taught to ALWAYS leave your mags 2 rounds short. Is this still true today, or is this rule for older style mags? I heard some people say that springs today are better than years ago and spring fatigue is no longer an issue. True or False? Thank you…

    1. The recommendation to load 28 instead of 30 was to address two specific issues with the GI magazines in use at the time.

      1) When fully loaded to 30 rounds, there wasn’t enough slack left in the spring for the magazine to be inserted with the bolt closed.
      2) Taking only one round out (29) switched the first round to the other side of the magazine, which for some reason could cause problems reliably feeding that first round.

      Loading only 28 rounds kept the first round on the same side as with 30 while also giving the spring room to compress under a closed bolt.

      Many newer magazines are designed with springs that will permit loading a full 30 rounds under a closed bolt, so the answer today is “it depends on the magazine”. If a fully-loaded magazine if your chosen brand seats easily under a closed bolt, then you don’t need to worry about it.

  8. I have a great many magazines for all my pistols and semi auto rifles and I keep about 6 each of the magazines fully loaded on a seven day rotation and then swap them out for a fresh set of 6 or so depending on the firearm. I really don’t experience many magazine problems and sometimes it is actually the ammo not the mag. I don’t like my springs too tight and by doing this type of rotation they don’t become overly loose and do loosen up just enough not to create and problems. I, also, never go plus one and simply fill the magazine to capacity and cycle in the first round for my carry pistols. I also buy decent mags like magpul, tapco, and factory magazines for specific firearms.

  9. I’m one of those people who own quite a few Viet-Nam era Colt 20 rounders and very seldom use 30 rounders as I go the majority of my shooting off the bench and the 30 rounders just get in the way.
    I have replaced the followers and in a few of them the spring but all in all they work just as well today as they did 40 years ago.
    I do disassemble all mags once a year and clean the insides and test the springs.
    I do agree with Geoff’s comment that if a mag fails get rid of it or salvage the follower and spring for spare parts.
    I’ve found that in most cases failure comes from weak poorly formed lips. While I won’t name companies that produce crappy mags, trust me, they are out there.

  10. Great article i am still using GI mags that i had acquired in Nam,have added others to my stock pile.yes i have been slacking in my maintenance on my mags,there is no free ride,i also never load my mags to the max usually keep 2rds shy that is my input again great article,Bill

  11. Good article! I wonder if I can apply it to my 14 rd. Paraordnance .45 mags. I’ve found that if I leave more than 10 rds in them for a long period they will feed only a few rounds before hanging up.

  12. Instead of attempting to repair a magazine, just circular file it. If I determine that a failure is magazine induced, and is not reduced upon routine cleaning, then that magazine is trash.

    Is your weapon failing at a critical moment, whether that be during a hunt, competition, or a fight, worth the relatively small cost of a single magazine? If your life is worth more than $30, $40, or more, trash the questionable magazine and move on.

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