What is a buffer tube?

A buffer tube, also known as a receiver extension tube, is the cylindrical aluminum housing that holds the buffer and spring in an AR-15/M4-style rifle.

The buffer tube serves two main purposes: to house the reciprocating mass (buffer and spring) of the bolt carrier group, and to provide a mount for Buttstocks.

Buffer tubes come in two different diameters: mil-spec (1.148”) and commercial (1.168”). Commercial diameter tubes are slightly larger in order to accommodate for aftermarket stocks, while mil-spec tubes are designed to fit only mil-spec dimensioned stocks.

There are three different length buffer tubes available on the market: Rifle length (12”), Carbine length (9.5”), and Pistol length (7”). The different lengths of tubes are designed to work in concert with different size barrels and gas systems.

A buffer tube, also known as a buttstock extension or receiver extension, is the cylindrical aluminum tube that houses the buffer and spring on AR-15 and M4 Carbine style rifles or pistols. Your rifle’s action Spring sits inside the buffer tube and the Buffer Assembly (made up of smaller springs and weights) fits over that. The entire assembly is housed in the stock, with the exception of the castle nut which is threadily attached to keep it all in place. When you pull back on your charging handle, forces created byvthe compressed spring cause downward pressure on yourbcbuffer assembly allowing it to push refreshingly new rounds into your chamber as fastas you can physically manage.

There are a few factors you’ll want to consider when shopping for a new buffer tube:

– Material: Aluminum is by far the most popular choice for buffer tubes due to its light weight and durability. Some manufacturers offer options in steel or polymer, but these are generally heavier and don’t offer any real benefits over aluminum.

– Diameter: Most commercial ARs will come with a mil-spec diameter tube which is 1.148″ in diameter. There are also “commercial spec” tubes which have a slightly larger diameter of 1.168″. These are completely compatible with mil-spec stocks and buffers, but some users prefer the slightly larger diameter for a better fit in their hands.

– Length: Buffer tubes come in two lengths: carbine length (7″) and rifle length (9″). The length you need will be determined by the stock you plan to use. Carbine length stocks will only work with carbine length tubes and visa versa.

– Profile: Buffer tubes are available in either mil-spec or commercial spec, and can also be had in “flat top” configuration. Mil-spec diameter tubes will have a small lip at the back which is there to prevent the stock from sliding off in the event of a fall. Commercial spec tubes have a slightly larger diameter and lack this lip. Flat top buffer tubes are machined without the lip and have a completely flat edge all the way around. These are generally only used on race guns or competition rifles where weight is critical.

A buffer tube is a component of a firearm that allows the action to cycle smoothly. It is typically located between the receiver and the buttstock. The buffer tube contains a recoil spring and a buffer, which help to absorb the force of the gun firing and return the weapon to its rest position. Buffer tubes can be made from different materials, such as aluminum or polymer, and come in different sizes to accommodate different types of firearms.

A buffer tube is a device that is used to store ammunition in a firearms. It consists of a hollow cylindrical casing that is attached to the firearm and has a spring-loaded plate inside of it. This plate holds the rounds of ammunition in place so that they can be fed into the gun’s chamber.

A buffer tube is part of a rifle that holds the spring and buffer assembly that helps actuate the bolt carrier group. The action of the BCG cycling reciprocates the spring which is held under tension in the buffer tube. This absorbed kinetic energy makes for a softer shooting rifle. Excess gas is also vented out of the port in order to reduce felt recoil.