Building a short barrel rifle from a kit? One of the parts that often gets overlooked is the buffer tube, specifically the buffer weight.
However, the buffer tube system plays a vital, central role in cycling the action of gas-powered rifles, such as AR-style platforms.
Here’s what to know about buffer systems and weights.
The Role of the Buffer Tube
This buffer tube, which mounts to the lower receiver, is an aluminum tube that contains a series of weights and a spring.
When you fire an AR-style rifle, when the bolt carrier group unlocks, it moves backwards as a result of pressure due to gas impingement.
To move rearward, it must work against the mass of the buffer weights, and then compress the buffer spring, which slows and ultimately arrests its rearward progress.
Then the energy stored in the spring is responsible for resetting the bolt carrier group by sending it back into battery.
The heavier the buffer weight, the higher the static mass of the rifle and the lower the felt recoil will be. The lighter the weight, the snappier the action’s cycling will be, but felt recoil will increase.
Using a weight that is too heavy will also hamper cycling, so it’s important to align the buffer weight with the chambering as well as with the length of the barrel.
What Are the Main Weights in Buffer Tube Kits
There are six main standard buffer weights for AR rifles. These are as follows.
- Pistol buffer: Pistol buffers usually weigh between 5 and 8.5 ounces and are usually used with PCCs (pistol-caliber carbines) that do not have gas actions. Instead, PCCs typically have direct blowback actions that are more reliable with pistol cartridges. The reason for the heavier buffer weight is because direct blowback action typically produces pretty high felt recoil; the heavier weight helps to absorb some of that.
- Carbine buffer: Carbine buffer tube kits typically contain 3 ounce weights. These are among the lightest buffer weights out there and they are also among the most commonly encountered in AR-15 builds. Because it is so light, it works with almost any caliber and cartridge, including many types of subsonic ammo, and with both carbine and mid-length gas systems. Just be aware that, since it is so light, with heavier bullets and calibers it will produce greater felt recoil.
- H1 buffer: H1 buffers are slightly heavier than carbine buffers at 3.8 ounces. This means they reduce recoil slightly better and are more reliable with mid and rifle-length gas systems. Like carbine buffers, however, they are also incredibly versatile and can be used with a wide range of cartridges.
- H2 buffer: At 4.6 ounces, H2 buffers are almost a whole ounce heavier than H1 buffers. Despite the heavier weight, an H2 buffer will still perform well in a carbine-length or mid-length gas system, and will do a better job of mitigating felt recoil. Almost any rifle, regardless of chambering, can run an H2 buffer if the barrel length is between 14 and 16 inches. As a result, H2 buffer weights are a common pairing with short barrel rifles.
- H3 buffer: H3 buffers weigh between 5 and 5.4 ounces, and are among the heaviest buffers commonly in use. They are commonly used in 5.56 ARs that are overgassed as well as AR style rifles in heavier chamberings. Generally speaking, the higher the muzzle energy, the heavier the buffer weight should be. Also, these heavier weights will help mitigate recoil.
- Rifle buffer: Rifle buffers weigh 5 ounces, but the main difference is that rifle-length buffer tubes and buffer springs are longer than carbine-length tubes and springs.
What’s the Best Buffer Weight for a Short Barrel Rifle
More than one buffer weight can be successfully used with a short barrel rifle kit, but if you’re looking for a good option, chances are an H2 buffer weight is a good option because it will perform well with short barrels.
How Else to Mitigate Recoil
The buffer weight is only one aspect of recoil mitigation. If you’re looking for other ways to cut recoil with your short barrel rifle, here are two good ways.
- Muzzle brakes and suppressors: Both muzzle brakes and suppressors will cut felt recoil, in some cases by as much as 50%. In the case of a suppressor, not only will it reduce recoil, but it will also boost muzzle velocity slightly, while also mitigating muzzle pop.
- Shoot rounds loaded with lighter bullets: If you really like your current outfit and don’t want to make any changes, one thing you can do is tinker with the ammo. Shoot loads with lighter bullets, which will reduce muzzle energy; this action will lower felt recoil.
Hopefully you found this information on buffer tube kits, weights, and recoil reduction for short barrel rifles helpful. If you still have questions, get in touch with us at Sales@MCSGearup.com and we will do our best to help.