Difference Between AR-15 Buffer Springs

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!