Let’s speak about how to choose the best buffer for your next project. The AR-15 platform’s many components receive a lot of attention. Each shooter has a different perspective on which is the most necessary to ensure that their gun functions properly.
For accuracy, a good barrel or trigger is essential. A good receiver set may serve as a firm foundation for the rest of the components. It’s even possible to claim that a decent optic allows a plinker to function as a precision rifle.
However, I will argue for a different component: the buffer. It may not be the most crucial component, but it is essential to the flawless operation of the entire system.
- 1 Beginner’s Buffers
- 2 Choosing an Appropriate Weight
- 3 Weight Rule of Thumb
- 4 Sizes of Common Buffers:
- 5 AR15 Buffer Weight Chart
- 6 Tune your AR15 by Tweaking the Buffer Weight
- 7 FAQs
First, the AR’s cyclic action is set in motion by the buffer and buffer spring, which are contained within the buffer tube. The bolt carrier group (BCG) contacts the buffer as it moves rearward within the tube after a shot is fired, and the weight of the buffer and tension in the spring resists the BCG’s rearward movement.
The BCG is pushed forward when the buffer tube components recoil. While all direct impingement AR rifles work in much the same way, buffers come in two sizes (rifle length and carbine length).
The most crucial point to remember here is that these two sizes are not interchangeable. For the sake of this post, we’ll concentrate on buffers for carbine rifles.
Choosing an Appropriate Weight
A typical method of “tuning” a rifle is to use various combinations of springs and buffers. It’s worth noting, though, that the buffer and buffer spring are just two elements of the puzzle.
The barrel length, gas port size, gas system length, suppressor use, rifle caliber, and other factors all influence how efficiently the weapon controls gas during gas system cycling.
The longer it takes to shift the buffer, the heavier it is. It will help smooth down the recoil and slow down faster. However, using a buffer that is too hefty might cause the rifle to short-stroke (i.e. not fully cycled, resulting in inconsistencies in extraction and ejection).
Weight Rule of Thumb
The general guideline is to choose the heaviest bullet that will enable your rifle to fully cycle, extract and expel the spent casing, and load a fresh round into the chamber.
A normal carbine buffer is the best option for most designs. Occasionally, though, you may discover that the gas port on the barrel is somewhat larger.
This can result in your BCG traveling too quickly, forceful extraction, and other issues. This is done by barrel manufacturers to ensure that their guns will still fire when customers use less powerful ammunition.
Make a note of how the spent casings are ejected if you want to see whether your system is overgassed. The ideal ejection will send spent casings in the direction of 3-4 o’clock. The mechanism is overgassed if it throws the casings ahead of the shooter.
In this case, going heavier will slow down the BCG and result in better performance, as well as enabling more gas and carbon to escape the weapon, resulting in cleaner operation overall.
Sizes of Common Buffers:
Carbine – 3 oz.
This is particularly frequent in gas systems with a carbine length. It’s designed to function with a variety of ammunition and can even be utilized in some mid-length gas systems.
Heavy (H) – 3.8oz.
The first of the “heavy” buffers, and the lightest (also called an H1 buffer). Switching to an H is the most typical recommendation if you’re having problems with a hard running machine or obtaining aggressive or irregular extraction.
H2 – 4.6 oz – 4.7oz.
This may be employed in certain mid-length systems, but the most typical application is in handgun constructions with sub-16 inch barrels to compensate for the action’s more severe cycling. If you have a fully automatic weapon or shoot a lot of 5.56 NATO, an H2 could be the way to go.
H3 – 5.0 oz to 5.4 oz.
With calibers like 7.62X39,.300 AAC,.224 Valkyrie,.458 SOCOM, and the.50 Beowulf is available for the AR platform, an extremely hefty buffer is recommended. On these builds, the H3, as well as the HSS and XH, fit the bill.
Pistol Caliber Builds – 5.0 oz. – 8.5 oz.
Because it’s a pistol caliber construction, there’s no standard gas system to mitigate the blow the BCG sends to the buffer. This, along with the fact that BCGs are often heavier in mass, necessitates the employment of a bigger buffer to smooth the action and ensure dependable operating.
For blow-back systems, there are additional longer PCC buffers. Due to the lack of a bolt, the BCGs utilized are shorter. Using a typical carbine buffer, results in needless overtravel. This implies that the bolt builds up more force as it returns home, putting unnecessary stress on the bolt catch on LRBHO PCC designs.
AR15 Buffer Weight Chart
Using the chart above as a starting point and guideline for adjusting your rifle is a wonderful idea.
The length of the barrel, the kind of gas system, whether you’re firing suppressed or not, and the caliber of the rifle all have an impact on how efficiently the rifle controls the gas, resulting in felt recoil.
Tune your AR15 by Tweaking the Buffer Weight
The bolt carrier group (BCG) experiences increased resistance as it advances backward with a heavier buffer weight. As a result, the entire motion, particularly the felt recoil, becomes smoother. It’s also not beneficial for a rifle to have a buffer weight that is excessively hefty. The AR-15 will not cycle properly if it is excessively heavy, resulting in extraction and ejection failures.
The general guideline is to use the largest buffer weight that will allow your AR-15 to cycle completely, remove and expel the spent casing, and load a fresh round into the chamber.
Step up to the next buffer weight if it’s currently cycling well but the recoil is still too snappy. Drop the buffer weight back around one and test whether your AR-15 is not locking back on an unloaded weapon or any other issues.
What is the normal AR-15 buffer weight?
Buffer weights for the AR-15 are available in a variety of weights and lengths. A normal carbine buffer should be around 3 ounces in weight. An H1 buffer weight, often known as a Heavy Buffer, is nearly a full ounce heavier, weighing 3.8 ounces. The H2 buffer weight should be between 4.6 and 4.7 ounces in weight.
Is it true that a heavier buffer reduces recoil?
If your AR-15 is over-gassed, as many are, and you don’t have an adjustable gas block, a bigger buffer weight like the H2 can reduce perceived recoil significantly.
What buffer size do I use for an AR-15?
H2 buffer weights are perfect for mid-length gas systems, but they’re also showing up in AR pistol setups with barrels under 16 inches to smooth down the cyclic motion. If you’re using a 5.56 NATO round, an H2 buffer weight is a way to go.