When you are building your first rifle and aren’t sure about how to pick out a barrel or what the difference is between the different types, wouldn’t it be helpful to have a resource to help you? Lucky for you, this article is exactly that. To help you decide what kind of barrel is right for your next AR 15 build, we have created this reference sheet that goes over some of the most popular types of AR 15 barrels available on the market today.
Chrome Moly Vanadium Steel
Chrome Moly Vanadium (CMV) is one of the most common types of barrels we see on the market today. This type of steel is a hard, strong steel that comes in several forms including 4140 and 4150. 4150 CMV is known for being used in the United States military, but very little difference can be noticed between the two applications. Be careful not to confuse CMV with being a Chrome lined barrel because they are NOT the same.
Another commonly used steel for rifle barrels is Stainless Steel. This type of steel is more malleable which allows barrel makers the ability to manufacture the barrel with more precision. The finer precision during manufacturing contributes to a more accurate barrel. Stainless Steel barrels are known for being heavier with higher velocity, but are often more expensive some times costing twice what a chrome lined barrel would. Also while they have corrosive resistant properties, they are not completely resistant and can corrode over time.
When choosing a barrel you will run into chrome lined vs non chrome lined options. A chrome lined barrel is created by adding a hard, slick coating surface to the bore of the barrel to help prevent rust and corrosion, and increase the life of the barrel. It is slightly less accurate than a non chrome lined barrel because of the coating and the possible inconsistencies in application including high and low spots, microscopic divots, and deficits that cause resistance to the round. As far as the wear and tear on the barrel, that really depends on the user and their choice of ammo, cleaning habits, and shooting environment. There is a trade off between accuracy and longevity.
A new comer to barrel technology is a process called Meloniting. Barrels treated with the Salt Nitride Meloniting process are more corrosive resistant and harder than chrome. Melonite is a molecular bonding process with the metal that allows the chemicals to seep below the surface of the metal instead of just a top layer. Unlike Chrome lined barrels, Melonited barrels do not give up any accuracy. Adams Arms’ barrels are finished with a QPQ Melonite process inside and out providing stainless steel velocities with complete protection. Using this process makes barrels more durable, more corrosive resistant, with increased lubricity.
There are many configurations of AR 15 barrel types and coating processes to choose from, but these are just some of the most popular to help you understand the basics. When choosing a barrel you need to consider factors such as ammunition, accuracy, longevity, and cost of the barrel. Do your research and choose what suits you best. Good luck and happy building!