Buffer tubes, springs and buffers play an integral part in a well-functioning AR-15 rifle. Finding the right buffer set-up for your AR-15 can be a challenge, especially on custom-built rifles. There are as many variations in buffer set-ups are there are rifles. Finding the proper equipment must be keyed to your rifle.
We have looked at the many variations in buffer tubes, springs, and buffers to compile our list. In many ways, the style of rifle and the caliber are the key issues in buffer selection. Anyone building an AR-15 must have a good understanding of how and why buffer tubes, buffers and buffer springs are so important.
AR-15 Buffer Assembly Components
Don’t ignore the buffer assembly on a standard AR-15 gas impingement rifle. If the buffer assembly is not properly assembled and tuned to the rifle, failures to cycle or feed properly can result. The first place to start with any discussion of buffer assemblies is examining the components of an AR-15 buffer assembly, how they work together, and their proper function.
The Buffer Assembly
The buffer tube on an AR-15 performs many functions other than just holding the buttstock on the rifle. Holding the buttstock is, of course, an important function. However, it is what goes on inside the buffer tube that is most important to the proper operation of an AR-15.
The Parts of your Buffer Assembly
There are several parts to the buffer assembly. We have already briefly discussed the buffer tube and its role in holding and contain the other parts. The remaining parts of the buffer assembly include:
- The buffer
- Buffer weights
- A buffer spring
How it all Operates
During the operation of your AR-15, the buffer spring and buffer are responsible for several functions.
- The buffer and buffer spring help absorb and mitigate recoil as the bolt carrier groups are propelled backward by the gas impinging on the bolt carrier
- At the end of the cycle, the bolt carrier spring forces the bolt carrier back into battery.
- During the return to battery, the bolt carrier group picks up a fresh round from the magazine.
It is easy to see that the buffer, buffer spring, and buffer tube all contribute to the reliable operation of your AR-15 during firing.
Many AR-15 shooters are familiar with the buffer tube, buffer, and buffer spring. The weights that ride inside the buffer are important yet often overlooked components of the system. The inertia that the weight of the buffer provides helps manage the overall cycling of the rifle.
Too little weight in the buffer, and you may experience hard recoils and failures to feed properly. Too much weight can soften recoil but may result in short-cycling the bolt carrier groups and more failure to feed problems.
Tuning the weights in the buffer can be the difference in an AR-15 that cycles easily and reliably while providing a comfortable shooting experience. Too much or too little weight in the buffer can cause excessive wear on your rifle.
Kits or Parts – Which Way to Go
Most AR-15 builders purchase a buffer tube kit that includes the buffer tube, buffer spring, buffer, and weights. Buying a kit is convenient and often cheaper than buying individual parts. In general, buffer kits work well for standard AR-15 builds, and most shooters will not experience any problems.
However, there are some instances when buying individual parts for your buffer assembly can give you better performance.
- A non-standard rifle build almost always requires tuning a buffer assembly to the rifle.
- If you intend to shoot sub-sonic ammunition in a suppressed rifle, a custom buffer assembly is almost a must.
- Larger calibers require buffers tuned for the heavier recoil and large bullets.
A stock carbine or rifle length AR-15 chambered for .223 Remington or NATO 5.56 ammunition typically does not need a custom-tuned buffer assembly. The performance of these calibers and regular bullet weights is well known and buffer manufacturers provide equipment that matches these configurations.
Buffer Weights – Finding the Right Balance
Most AR-15 builders and shooters are unaware that buffer weights can be changed and adjusted to suit your rifle and ammunition. Deciding on the correct buffer weight is influenced by several factors.
- Barrel length
- Barrel weight
- Caliber of ammunition
- Gas tube length
- Buffer tube length
Typically, buffer weights are classified as follows.
- Carbine length rifles (3.0 oz.)
- Heavy Barrel Rifles (3.8 oz.)
- H2 (4.7 oz.)
- H3 (5.0 oz.)
- HSS (6.5 oz.)
- XH (8.5 oz.)
These weights don’t consider the ammunition you shoot or the bullet’s speed.
The Buffer, the Heart of the Buffer Assembly
It takes all the parts of a buffer assembly to operate an AR-15. However, the buffer itself is the key piece of the assembly and should get the most consideration. The most critical decision about an AR-15 buffer, apart from its weight, is the material from which it is made. There are three options available to most shooters building an AR-15.
- Aluminum – The lightest material available for buffers is aluminum. Most aluminum buffers weigh in at about .25 ounces. A quarter of an ounce is extremely light and is usually only found in custom rifles built for precision competition shooting.
- Steel – Steel is probably the most common material used for standard AR-15 builds. A typical steel buffer for a standard AR weighs in at about .65 ounces. Most commercially available buffer kits have steel buffers and these systems perform reliably and efficiently in most cases.
- Tungsten – Tungsten is hard and heavy. Where extra weight in a buffer is needed or extreme wear and tear are anticipated, tungsten buffers are a good choice. Most tungsten buffers weigh a bit more than steel buffers.
Buffer Springs – Not Just a Coil of Metal
The last part of the buffer assembly is the buffer spring. Like almost every other part, buffer springs come in different sizes and styles.
- Carbine Springs that measures 10.5” with 37 to 39 coils
- Rifle Spring that measures 12.75” with 41 to 42 coils
AR-15’s are known for the distinctive sound made by a buffer spring inside the buffer tube as it operates. Some people refer to this as a “twang,” while others liken it to a slapping sound. However you call it, this sound is annoying to some shooters. Installing a captured buffer spring in your AR can eliminate much of this sound when firing the rifle.
Our Buffer Suggestions
No matter your preference, a custom-built buffer assembly or a kit, we have examined the market and found what we think are the best options in each category. Our best of buffer list includes individual parts and kits. It is up to you to decide which option is your best choice.
Best Rifle Length Buffer Kit – Brownells AR-15 Rifle Receiver Extension & Buffer Kit
If your rifle choice is a mil-spec full-length AR-15, the Brownells AR-15 buffer kit is a solid choice. This kit fits a standard AR-15 or M16 lower without modifications. The aluminum tube construction keeps weight down yet provides strength and durability to your rifle. Brownells AR-15 buffer kit comes standard with these features and parts
- Made from mil-spec 7075 aluminum
- Matte black hard anodized finish
- 9-5/8 inch length
- 1.110-inch diameter
- The kit includes the buffer tube, buffer, and buffer spring
The Brownells rifle length buffer kit takes the guesswork out of putting together a reliable buffer assembly for your rifle length AR-15. The l styling of a fixed stock AR-15 appeals to many shooters and this buffer assembly makes the job of assembling a rifle easy and quick.
Best Carbine Length Buffer Kit – Aero Precision AR Carbine Buffer Kit
The carbine length AR-15 is probably the most popular AR build. These shorter and more compact rifles are easy to shoot and convenient to transport. If you anticipate building a carbine length AR-15, the Aero Precision carbine buffer kit is a great option.
Aero Precision offers a more complete kit than some manufacturers, which is a big plus. Feature-wise, the Aero Precision carbine buffer kits aren’t lacking at all.
- Made in the USA
- Six position mil-spec 7075 aluminum construction
- Carbine length buffer tube
- Carbine buffer
- Includes the endplate and locknut
- 3.25-inch buffer length
- Buffer weight – three ounces
The convenience and speed with which a solid, dependable AR-15 carbine can be built using the Aero Precision carbine buffer kit can be built is without argument. Aero Precision is known for its quality and consistency. You can have confidence in your rifle with an Aero Precision carbine buffer kit installed.
Best AR-15 Buffer for Suppressed Rifles – Griffin Armament AR-15 SOB (Suppressor Optimized Buffer) Gen 2
Building a suppressed AR-15 can be a challenge depending on your choice of caliber and barrel length. It is almost a given that to maximize the effect of your suppressor, you must shoot subsonic ammunition. Going subsonic means a buffer system tuned specifically for this kind of shooting.
Griffin Armament offers a buffer specifically for suppressed rifles. The Griffin Armament AR-15 SOB is a precision-built buffer that can easily match the characteristics of your suppressed AR. The features that Griffin offers make this buffer highly attractive to suppressed rifle shooters.
- A spring-loaded buffer featuring a staggered impact design
- Urethane buffering for superior shock resistance
- Weighs 4.9 ounces
- Brass weights for more consistent operation
- Machined from 17-4 stainless steel
- Fully tunable for maximum efficiency
If a suppressed AR-15 is in your future, the Griffin Armament SOB buffer should be on the list as well. Many shooters overlook the importance of a buffer, especially in a subsonic suppressed rifle. Griffin Armament has filled the void for suppressed rifle shooters with this buffer.
Best AR-15 Buffer Spring – Damage Industries Buffer Springs
An often overlooked way to enhance the operation of your AR-15 is changing the buffer spring. The buffer spring provides the oomph to return to buffer and bolt carrier to the forward positions. A buffer spring that does this consistently and efficiently can add just a little extra to your rifle operation.
Damage Industries have a reputation for consistency in their production that instills confidence that the buffer spring provides efficient and effective operation. The features of these springs speak for themselves.
- Clean surfaces produce less friction and drag in the buffer tube
- Precision manufacturing delivers springs with a long life of consistent operation
- Affordable prices are a great added feature
- Manufactured to mil-spec or better standards
For the price it costs, upgrading your buffer spring can be one of the best ways to enhance your rifle’s operation. Don’t overlook a part of your rifle that performs such a vital function.
Best AR-15 Buffer Tubes – BCM® Milspec Carbine Receiver Extension (Buffer Tube) 6 Position
Buffers and buffer tubes are not something that usually gets a lot of attention because of their looks. However, when you consider that fit and finish are just as critical to the buffer assembly as any other part of your rifle, these factors take on a new significance.
Bravo Company produces an entire line of AR-15 parts and accessories. Their buffer tubes are, in our opinion, some of the nicest available at a reasonable price. The fit, finish, and look of the Bravo Company buffer tubes offer numerous advantages. Apart from looking great, these buffer tubes offer several advantages.
- Machined from 7075T6 aluminum
- Manufactured to mil-spec dimensions and specifications
- Hard Coat Anodized per Mil-A-8625F, Type III, Class 2 specifications
You may not see much of your buffer tube assembly when your rifle is complete and operational. However, the visual clues to quality and superior operation are unmistakable. Bravo Company meets the test for buffer tubes that perform operationally and visually.
Getting the Best Bang Out of Your AR-15
You may be building a generic AR-15 rifle or carbine. Your build may also be a one-off custom job that meets special requirements. In any case, the buffer assembly is critical to the proper operation of your rifle. Making the bests choices for the parts of your buffer assembly are a significant part of any AR-15 build.
We hope this article has helped you understand the importance of your AR-15 buffer assembly and the importance of carefully crafting and tuning the buffer assembly for your rifle. If you have ideas or suggestions, please share them in the comments section below. We appreciate your insight and your knowledge. Be safe and shoot straight.