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Wade writes:

How can you eliminate the rattling in a sliding AR-15 stock? I’ve tried several kinds, but they all rattle and make quite a bit of noise. Short of duct-taping them in place, I can’t prevent this.

It’s terrible when an otherwise good gun is ruined by a crappy stock. Thankfully there are some options out there to fix this issue.

The problem our reader is describing is the movement in a sliding AR-15 stock. The stocks are designed to be collapsible in order to accommodate all size shooters and let them properly adjust the stock length (or “length of pull”) to suit their own style and physical size. In order to make the stock slide back and forth easily the designers don’t typically design stocks with very tight tolerances which leaves plenty of space for the stock to move back and forth. There are four solutions to this issue.

Solution 1: Ignore it.

If you’ve listened to the Car Talk radio show long enough you’ll hear them mention using electrical tape over the “check engine” light for really old cars. The same solution works equally well for this situation. If the stock isn’t bothering you too much then just ignore it, as any solution will require you to spend some extra cash and break out the toolbox.

Solution 2: Fixed Stock

Collapsible stocks are great, but fixed stocks work equally as well. The Marine Corps still uses fixed stocks on their standard infantry rifles and they don’t seem to have an issue with it, and swapping out your collapsible stock for a fixed stock will eliminate any movement.

There are two options for fixed stocks, either you get a milspec stock (such as the A1 or A2 stock) that is identical to the M-16 stock, or you get a new production stock like the Magpul PRS. What you’re using the rifle for will determine which stock is best for you, as “tactical” rifles will be better suited with an A1 or A2 stock and “precision” rifles will be better suited with modern stocks. Some people also prefer the ARFX style skeleton stock that cuts down on weight and has a comfortable cheek pad.

For either option the buffer tube will need to be replaced on your AR-15 rifle. This is the black tube that your bolt carrier and buffer assembly slide in and out of when the gun cycles, and also where the collapsible stock attaches to the rifle. While collapsible stocks require the buffer tube to be positioned a certain way using a castle nut and have a boxy protrusion underneath them, fixed stocks use a smooth buffer tube that screws on flush to the receiver. After swapping out the buffer tube follow the manufacturer’s instructions to finish the installation. Total time for the fix should be less than 30 minutes.

Solution 3: Solid Adjustable Stocks

A number of manufacturers have come out with stocks that combine the adjustability of a collapsible stock with the rigidity of a fixed stock, most notably Magpul with their UBR or “Utility Battle Rifle” stock. It uses a proprietary buffer tube and sleeve system (so yes, you will have to swap out your buffer tube) along which the actual buttstock travels. The sleeve has grooves and notches that keep the buttstock firmly in place wherever you want it and doesn’t let it wiggle at all. I like it so much I put it on my competition rifle and it works perfectly. The lead image is a picture of my gun lying in a field during the 2011 FNH 3-Gun Nation Championship in West Virginia yesterday.

There are other manufacturers that have similar products that do the same thing. I know of one company (whose name escapes me) that makes stocks which are adjustable only by the use of a screwdriver and so lets people get around assault weapons bans. As a side effect it also creates a solid stock that can be adjusted and won’t move around.

Solution 4: Fix it

The last solution to fixing your wobbly stock is to fix it in place yourself, turning your collapsible stock into a fixed stock. Depending on what kind of stock you have and how wobbly it is will dictate exactly how to fix it in place, but the general process is to place enough material at the back of the stock behind the buffer tube to keep it from collapsing any farther and then liberally applying super glue to the tube before shoving the stock back on. I do NOT recommend this method, but it is an option.

IN SHORT, the best solution is to swap out your stock for either a fixed or a more solid stock. The way that collapsible stocks are designed and manufactured makes them wobble, and I haven’t come across a collapsible stock yet that uses the standard collapsible stock buffer tube and doesn’t have some major issues. There are options available, but the good ones require a little minor gunsmithing.

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  1. Or just take it to your favorite gun smith and see what they can do for you. I would much rather pay someone to fix a $200 dollar part than ruining it myself. Plus if you are lucky you might get some tips out of the deal.

    • Or you can save your money and fix it yourself… you will learn more and a wobbly stock? Seriously? It’s a gun… a tool. I’ll never understand these guys that treat their ARs like 10,000$ over and under shotguns. If you are shooting enough and not just playing with it like a toy you wont hear the rattle anyways.

      • My CTR tightens right up with zero wobble, shake, or wiggle. If it doesn’t, make sure you’re not running a Commercial stock on a Milspec receiver extension.

        • Mr Normal hit the nail on the head!! I’d bet dollars to donuts that’s the problem! It has to be mil spec to mil spec otherwise you are going to be loose! Can’t go the other way….mil spec won’t go on a commercial buffer tube. Ronaldo hit it too! Also make sure your buffer spring is the right length for the tube you are using. Don’t use a collapsible spring in a military full size stock. Go to Damage Industries and get a Chrome Silicon spring for a completely reasonable price, might even get it on special, around $10.00 or a bit more. Quiets it right up and also lasts more than a standard stock spring. 5000 rounds stock to 50,000 cycles before it wears out. Yes, they wear out, depending on quality of spring. Mines quiet as could be, smooth as silk and runs awesome. Make sure your buffer isn’t too heavy too. If you start changing things, they need to be tuned, check out YouTube! Good explanations. Good luck!

      • Yup. If rattle really bothers someone, then the Wilson, now Colt, superstoc is the way to go.

        Although I have heard you can take a bolt and turn a MOE stock into a CTR locking type.

  2. Could it be a commercial stock on a mil-spec buffer tube?
    Milspec buffer tube diameter is 1.148″ 7075 forged aluminum and has a flat end.
    Commercial buffer tube diameter is 1.168″ 6061 extruded aluminum and has a slanted end.

  3. I, for one, don’t see much value in a sliding stock. The length of my arms hasn’t changed in 30 years, and if other shooters don’t like the length of my AR then too bad. The purpose of a collapsing stock is not to accomodate different sized shooters, but to make the rifle compact for such things as jumping. Not many shooters outside of the military jump with their rifles.

    If you look at other, better types of rifles than the AR15, you’ll notice that instead of collapsing stocks they have folding stocks, which have only two positions, deployed or folded, and are very solid with no play or rattle. My DSA Para rifle’s folding stock is strong enough to buttstroke a gorilla and doesn’t rattle. Try buttstroking anything harder than a pillow with a CAR type collapsing stock and you’ll have a broken rifle.

    I’m afraid the CAR type stock is of a piece with the rest of the AR15 platform: Crap.

  4. One could order a New York compliant rifle. Many ARs here have pinned collapsible stocks that give the tactical appearance without play. Of course you lose the flash hider for what that’s worth. Food for thought.

  5. If you shake an AR with a fixed stock, the recoil buffer is going to rattle. When I first handled an M-16 in 1967, it rattled like a baby’s teething toy. AR-15s rattle a lot less, but they still rattle when you shake ’em, just not when you shoot ’em.

  6. I never wear a vest and I only have one length of pull. I.e. my arms stay the same length so I always opt for fixed stocks.

  7. Some may not find the need for a collapsible stock, but I find them indispensable.
    The spot in tractor is 33″, the combine has the same area available. I have a bit more room available in the truck.
    I live in Kansas. On December 6th it could be 75°F or it could be -10° F, and those layers do make a difference. Actually at sunup it could be -10° F and at sundown just cooling down from 75° F in the same day.

  8. Not having the money for one of the really nice adjustables I put a fixed stock on mine, an A2 style I think. I like the extra storage space in the butt and it makes it feel a lot more solid. Given the chance I would probably go with one of those Magpul models though.

  9. All I do as a removable solution is take a strip of electrical or duct tape, tape the bottom of my buffer tube along the stock position divots, and cut slits on the tape above each divot point. This way when the stock’s pin digs into the divot, it’s a bit tight and it just about eliminates the majority of the wobble. No need for superglue or overweight stocks like the UBR on a typical carbine (I will admit they have their uses for balancing heavier rifles like SPRs or Recces).

  10. If you use your rifle in both hot and cold weather (wearing thick clothes), the adjustable stock is invaluable for proper fit and quick mounting. The Ergo F93 is an 8 position adjustable that is reported to lock up very solid with no rattle. I have not had my hands on one yet but hope to soon.

  11. Find a 2″ diameter clear plastic tube (mine came from a free city-offered cable gun lock-ah, the irony!). Cut two 3/4″ strips long enough to fit from just inside the rifle end to just short of where the buffer tube ends when the stock is in your favorite position (that way you can’t look into the hole and see the ends). Scuff both sides of the strips with a green Scotchbrite pad for friction reduction and to give tooth to the 5 or so pea sized dots of JB Kwik you will place on the stock side of each strip. Using tweezers, carefully place the strips inside the stock tube just above the channel for the lock. Twist the remaining piece of the clear plastic tube tight, insert inside the stock without touching the strips so that the open end is facing up away from the strips, and release-the pressure will help the strips seat tightly against the stock. Check quickly and carefully that the strips are where you want them, adjust as necessary and let dry for at least an hour before reassembly as you don’t want glue squeezing out onto the buffer tube (which should be oiled anyway as a precaution to keep a possible mistake in setting time from becoming a permanent installation). If all went right, your stock will be a very tight fit on the buffer tube but you will still be able to move it in and out by grasping the grip in one hand and pulling/pushing hard on the stock’s buttpad. If something goes wrong, you can pry the strips up and pull them out. The JB Kwik can be scraped off the stock and strips with a flat bladed screwdriver and you can then start over. Worked for me and I love my CAR stock-I’m so used to the solid feel now that I’m always shocked when I pick up a carbine and hear it rattle!

  12. Drop you stock in 150-185 degree f water let it sit for 2 minutes check fit after every additional minute the hot water shrinks the inner diameter where the tube goes in. Rattle gone guaranteed

  13. Just clip the end off of a plastic wire tie (I use about an inch) and wedge it into the space between the buffer tube and the sliding stock. I put it opposite of my cheek on the 2 o’clock position. Leave a little sticking out to grab if you want to remove it and you are done. Use Black wire/zip ties and only the close gawkers will know it is there. If they are that close to your gun they are friends or targets anyway.

  14. Drill a small hole in the underside of the stock, toward the front. Adjust stock to proper length. Install allen or phillips head set screw, of proper length to be flush, into hole until the stock tightens up. Do not over tighten or it will strip. Use locktite if you feel the need, but it should not back out if you use a set screw at least one size bigger than the drill bit used. I have used this method for years and thousands of rounds, yes you need a tool to adjust the stock, but really, how many times do you need to adjust it to fit your shoulder. Just my ¢2.

    • Thanks, this is the route I’m going to try….
      I just bought a 200 pack of assorted black set screws off ebay for under $9; what size do you like?

  15. I eliminated the rattle by inserting a 4″ long strip of metal the width of the tube slot and tapped it into place as a wedge. I put a hole in the end to pull it out if needed.

  16. Strips of Velcro on the tube will tighten it up a bit. Any noise from movement will be muffled by carefully placed strips. Don’t forget a few drops of super glue to keep the Velcro in place

  17. This is probably kind of ghetto – and I realize I’m very late to this article – but I had a pretty simple fix by just staggering and layering lines of black electrical tape on the top of the buffer tube. I prefer a mid-range length so my greatest thickness of electrical tape was in the center of the buffer tube – if you prefer shorter length stocks just layer the tape the thickest really close to the upper receiver. If you prefer longer length stocks just layer the tape the thickest really close to the end of the buffer tube. Worked like a charm, Stock has no more wobble or rattle, and feels snug constantly.

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