The Difference Between AR-15 Buffer Springs

Chome_Silicon_BuffSpring

The Purpose of the Buffer Spring

Buffer springs provide a very simple yet important purpose in a rifle. Each time the gun is cocked or a round is fired the bolt carrier has to follow through an action to load a round into the chamber. When the bolt carrier is either cocked back or pushed back it hits the buffer and buffer spring inside the buffer tube. This action pushes the bolt carrier forward to pick up a round.

To see this in action check out this great video:

The Different Types of Buffer Springs

Stainless Steel (SS)

Most Common Chemical Composition

ASTM Grade: A313

Elements: Chromium, Magnesium, Carbon, and Nickel

Compressions Cycles: 5,000 to 8,000 (shots)

Manufacturers: Colt, DPMS, JP, RRA, CMMG

(Note: Most AR-15 manufacturers make or label their own SS springs)

Cost: $4 to $20

Pros: Standard stainless steel buffer springs are very cheap and easy to find. There are numerous manufacturers and you rarely have to worry about quality, especially when it costs less than $5 dollars to replace one.

Cons: A stainless steel buffer spring only last for a few thousand rounds before you have to strip your rifle down and replace it. It is also very susceptible to high heat conditions that can occur through repeated fire. One of the most common complaints is that people do not realize these springs have such a short life which can cause malfunctions.

Chrome Silicon (CS)

Most Common Chemical Composition

ASTM Grade: A877 (Valve Spring Material)

Elements: Carbon, Manganese, Phosphorus, Sulfur, Silicon and Chromium

Compressions Cycles: 400,000 to 500,000 (shots)

Manufacturers: ISMI, Tubbs, Tactical Springs

(Note: Only select companies make these springs)

Cost: $20 to $40

Pros: Chrome silicon springs have a higher tensile strength, reduce recoil and can last up to 500,000 shots or more. They can also handle an increased amount of heat from repeated shots. In fact, they are so reliable that NASCAR, Formula One and Pro Stock car racers around the world use them in their cars. You also have to rarely worry about quality with these as only a handful of manufacturers produce them.

Cons: The only negative is the high price point.

TheARGuys Opinion

There are many individuals on forums and at the range that will tell you they have never changed their buffer spring and they never plan to do so. In fact, a lot of Army and Marines will say the same thing. What most of them don’t tell you is that they rarely if ever put 5,000 rounds through their guns or they have an armorer that does preventive maintenance on their rifles. In fact, the DoD has started to replace all buffer springs in rifles with chrome silicon in order to avoid additional maintenance so this argument is no longer valid.

One-way to avoid switching your spring every 5,000 rounds is to switch to a chrome silicon spring. Chrome silicon springs do cost more but in reality this is a small price to pay for the peace of mind. If you install a chrome silicon spring you will most likely never have to replace it!

 

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18 Responses

  1. ryan says:

    What’s the difference between rifle and carbine buffer springs

    • Aaron Brown says:

      The buffer spring will not change or impact the gun. Of course, there are a few exceptions to that rule. If you get a specialized buffer tube that is shorter or longer you will need to get a spring to match the length. Typically, if you buy a customer tube it will come with the proper spring. For instance, a lot of guys with gun trusts will turn their AR-15 in a short barrel rifle with a custom buffer. One other thing to note is that even know the buffer spring will not change you will most likely need to change the buffer itself. Carbine rifles typically use H buffers to compensate for the recoil. I hope that answers your question.

    • Dale says:

      “The springs for the rifle and the carbine are the same diameter, and made of the same steel alloy. The rifle springs have 41 to 43 coils, and the carbine springs have 37 to 39 coils. The brand-new length of the springs is approximately 12.75″ for the rifle and 10.5″ for the carbine springs.”
      Copied from gundigest.com.

  2. Nick says:

    My am15 misfires 6 or so out of every 120 shells. Any help would be great.

    Thanks
    Nick
    Love your posts

    • abraun says:

      Nick, This could be caused by a number of issues. To list the most common, are you having feeding issues? Do the rounds jam being fed into the barrel? If not are you having feeding issues from magazine to chamber/bolt? If so, might be cheap mags.

    • Nathan says:

      Do you have your springs on the trigger/ hammer installed properly. My first ar I had springs installed properly on the hammer but oriented shop the it wasn’t compressing but opening. That caused mood figures in my rifle. I fixed the issue. Since then shoots and cycles perfectly

    • Steve says:

      OIL – my M16 loved oil – when my AR started misfeeding, I used gun slick on the bolt and carrier group – as long as it was well lubricated, it worked flawlessly, but I did find some magazines it didn’t like also. When using the less compatible magazines, I found that holding them in the well or supporting the weapon on the mag would reduce or eliminate the misfeeds. My AR doesn’t particularly like the poly mags – loves the metal mags.

  3. Michael says:

    Hello, I recently bought the Ruger SR762. I am planning on putting on a Magpul UBR stock. The UBR Stock comes with a shorter buffer tube than the stock tube. The stock tube on the Ruger is extended because they use a longer buffer. That being said, I know that I am going to need to replace the spring and buffer but I was wondering on some advice for it. I was looking at Slash’s .308 anti-tilt Buffer and spring set. Would anyone be able to shed some light on if this is a good way to go or not? Thanks in advance.

  4. Eric says:

    I am building an AR 15 with a AR-Stoner Barrel AR-15 223 Remington (Wylde) HBAR Contour 1 in 8″ Twist 20″ Stainless Steel barrel with a rifle length gas tube. Do I install a rifle buffer (6″ long) with a Rifle length buffer spring?

    • abraun says:

      Yes, in this situation you would. May I ask why you choose a 1/8 twist?

    • Shadow says:

      I built almost identical rifle the UTG A2 stock came with buffer tube, buffer, and spring, the rifle was short stroking so started trouble shooting and I found nothing wrong till I counted coils on the buffer spring, 44 coils, have a new buffer spring on the way and it should solve my issues, getting a tubbs flat wire spring, put my upper on a friends carbine lower and fired without flaws, I thought it was a bit stiff pulling the charging handle back.

  5. Robert Hall says:

    Have a complete RRA 223 EOP Varmint rifle, 20 inch bull barrel with Ace SKeleton full size stock “ARFX”.
    I am buying a complete 458 socom 16 carbine upper to use for the RRA lower and stock mentioned above. majority of upper parts will be TRX to avoid reliability issues others have had with this sledge hammer. I’ve been told to change buffer to the H2. Currently have had no issue with rifle and have used it on multiple prairie dog hunts flawlessly, but that’s with 223. My question is what do you recommend on buffer spring and buffer? Should I just change just the buffer to H2, change spring and buffer or leave as is?

    • abraun says:

      I am assuming you are asking which buffer to use if you switch from 223 to 458? If that’s the case its recommended to switch to a heavier buffer. The upper was designed to be used with the standard buffer but that was because it was expected to only take a few shots to bust through doors and walls while in the field and they were not concerned with long term use. If you read through the forums you will find multiple opinions but the main one is to switch to a H2 buffer to avoid jams with a ton of shots.

  6. Robert says:

    Will a CS spring be a good match to an H buffer? If not what spring and buffer combo will work best with a carbine gas system?

    • abraun says:

      To be honest I would go with the LaRue buffer spring/buffer kit. Its a CS spring and paired buffer of the correct weight.

  7. Mike says:

    Please bear with me while I provide information so my question makes sense….

    I am building an AR 9 SBR. Using a designated Colt 9mm lower receiver. I have read some issues people have is that the the bolt will break the bolt catch. I found a Yankee Hill 9mm buffer (5.9 oz) that is longer than the normal buffer. The extra length is supposed to stop the breakage of the bolt catch because it shortens the distance traveled…

    The dealer that I purchased my designated lower from uses Wolf Extra Power Springs in all of their test rifles and state that buffer weight can vary between 4 oz – 8 oz, however, they don’t mention LENGTH of buffer.

    My question is: since I purchased a buffer that is longer should I use a different spring than the Wolf XP? Does length of buffer have anything to do with that?

    Thanks.

    Mike

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