Difference Between AR-15 Buffers

carbine_buffers_2_Before we get into the differences of each available buffer I would like to review the most important piece of information you need to know before selecting a buffer.

Purpose of the Buffer

The buffer is one of many pieces that helps your rifle to operate normally. When a bullet has fired the energy that it released pushes the bolt carrier backwards which then connects with the buffer within the buffer spring and tube. At the point of contact, the buffer pushes the spring backwards. Depending on the weight of the buffer and the strength of the spring the buffer will reconnect with the bolt carrier pushing a new bullet forward into the chamber to be fired.

Why does the weight of the buffer and strength of the spring matter?

We will start with the buffer spring. Most springs are fairly standard, but you will encounter different variations on the market. Look for the one that best aligns to your rifle and you will be fine. As for choosing the proper buffer weight that can be a little tricky. If you get a weight that is too heavy the rifle won’t be able to push the spring back and reload the weapon. If you get a buffer that is too light then bolt carrier might move too fast and not perform the proper functions. To learn more about the buffer weights, keep reading…

Buffer Weights

Now it’s time to get the reason you are here. What are the differences between each buffer that is offered on the market today?

Well, have a look….

Carbine Buffer (Avg 3.0 oz)



Includes 3 Steel Weights

Heavy (H) Buffer (Avg 3.8 oz)



Includes 1 Tungsten + 2 Steel Weights

H2 Buffer (Avg 4.7 oz)



Includes 2 Tungsten + 1 Steel Weights

H3 Buffer (Avg 5.6 oz)



Includes 3 Tungsten weights

Rifle Buffer (Avg 5.0 oz)



Includes 5 Steel Weights + 1 Steel Spacer

*Note that these are approximate weights. Each manufacturer creates products that range between the mil-spec standards.

One of the great benefits of a properly matched buffer and spring is the ability for the combo to reduce recoil! Everyone loves less recoil! But don’t get too excited, it takes proper care and matching of the buffer and spring to make sure that you are not reducing the energy to a point where the bolt carrier won’t reload the weapon.

What are buffers made of and why?

Most buffers on the market today are made of aluminum, steel, tungsten and rubber. You will notice from the chart below that the primary materials are Steel and Tungsten. The reason for this is because both metals are extremely heavy and dense. In fact, Tungsten is heavier than both Uranium and Gold while costing significantly less. The only metals that weigh more are Platinum, Iridium, and Osmium.

Type Weight*
Aluminum  .098lb PCI
Steel  .283lb PCI
Lead  .409lb PCI
Tungsten  .700lb PCI







*Note: Weight is measured per cubic inch (PCI) and is dependent on density.

What buffer is right for me?

This is the question everyone is trying to answer isn’t it! Like I said before when it comes to buffers it all depends on your setup. But when in doubt stick with a standard H buffer for collapsible stocks and rifle for a full-size stock.