H Buffer VS Carbine Buffer

In the world of AR-15 platforms, changing one component can skew the performance of a previously optimized rifle. Various components receive much attention and debate over their significance in ensuring optimal function. While components like the barrel, gas system, and bolt carrier group often take the spotlight, there is one critical piece that is often overlooked – the buffer. 

Though not the most prominent component, the buffer plays a crucial role in maintaining smooth operation in your rifle. In this article, we'll explore H buffer vs Carbine buffer, and how to choose the right one for your specific rifle setup.

Understanding the Buffer's Role

The buffer, along with the buffer spring, resides within the buffer tube and establishes the rhythm for the cyclic action of your AR's gas system. After firing a shot, the bolt carrier group moves rearward within the buffer tube and makes contact with the buffer.

The weight of the buffer and the tension in the spring resist this rearward movement, allowing the rifle's action to cycle effectively.

Importance of Buffer Weight

In general, heavier buffers will take longer to move and slow down the action, resulting in smoother recoil and improved operation. However, using an excessively heavy buffer can lead to short stroking, where the rifle fails to cycle fully, causing inconsistent extraction and ejection.

Two Main Buffer Sizes: Carbine and Rifle Length

Brownells AR-15 Rifle Buffer Tube Kit

Rifle Buffer

Carbine Buffer

While all direct impingement AR rifles function similarly, they come in two main buffer sizes: rifle length and carbine length buffers. These sizes are not interchangeable.

Choosing the Proper Buffer Weight

Selecting the appropriate buffer weight involves tuning your rifle using different combinations of spring and buffers. However, keep in mind that the buffer and buffer spring are just two pieces of the puzzle.

Other factors, such as barrel length, gas port size, gas system length, bolt carrier weight, suppressor usage, and caliber, will also impact how the rifle manages gases during its cycling.

The key here is to test them one by one. If the shell ejection pattern is forward of the 3 o'clock position, then that means the rifle is over gassed. This means the bolt is slamming too fast back, which makes the shell bounce off the deflector too hard.

Common Buffer Sizes and Their Applications

Let's take a closer look at some common buffer sizes and their applications:

  1. Carbine Buffer (3 ounces): The most common buffer for traditional carbine length gas systems. Works reliably with a wide range of ammo and some mid-link gas systems.

  2. Heavy Buffer (H or H1 - 3.8 ounces): Recommended if you encounter issues with a hard-running system or experience violent or erratic extraction.

  3. H2 Buffer (4.6 to 4.7 ounces): Often used in pistol builds with sub 16-inch barrels to offset the more aggressive cycling.

  4. H3 Buffer (5 to 5.4 ounces): Suitable for AR platforms in heavier calibers like 7.62x39, .300 AAC Blackout, 224 Valkyrie, 458 SOCOM, and 50 Beowulf.

  5. HSS Buffer (6.5 ounces) and XH Buffer (8.5 ounces): Recommended for specialized AR builds in heavier calibers.

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