May 01, 2023
The AR-15 is America’s most popular rifle because it is so easy to customize and maintain. Building an AR-15 from parts is also well within the capabilities of most rifle owners. Should you lack the tools necessary to put an AR-15 together, there is almost always a gunsmith or gun shop nearby that can assemble a rifle to your exact specifications. The advantage of building a rifle from parts you select is that you get exactly what you want without having to throw away brand new rifle components. Whether the goal is to build a new rifle from parts, to freshen up a tired rifle, or to customize an AR that isn’t as interesting as it used to be, selecting a barrel is one of the most important decisions to make.
The biggest mistake most AR enthusiasts commit is to buy what the government puts on issued M-4s and M-16s because the government must know what they’re doing. Right? Wrong. Those specifications were written in the 1950s and we can and should expect better from today’s modern manufacturing and materials handling. The barrel contours on issued rifles are also made to conveniently allow mounting a grenade launcher (in the case of the M-4), a capability that I don’t need or want because of its harmful effects on accuracy.
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Ballistic Modern Series
My first stop for a new AR-15 or AR-10 barrel is Ballistic Advantage because of the performance and value these barrels offer. Where the basic M-4 clone barrel is made from 4140 Chromoly steel and has a chrome-lined bore, Ballistic Advantage offers their “Modern Series”. These barrels are available in both 5.56x45mm and .300 Blackout, are made from the harder wearing 4150 Chromoly steel and have a superior finish.
The use of 4150 Chromoly steel is wise because of the higher carbon content it has over the more common 4140 steel. The additional carbon makes the steel harder and better equips it to resist the effects of throat erosion, although it is unlikely any 5.56x45mm barrel is ever going to see enough rounds to wear it out. The Modern Series barrels are available in the usual government contours for those that appreciate them, as well as “pencil” barrel contours for those looking to save weight. The lightweight barrels of the Modern Series are the ones that I like the best because the of the unique and sensible features they offer. The first being weight savings, second being the use of 4150 steel, and third being the use of QPQ finish.
“QPQ” stand for “quench, polish, quench” and is also known as “nitride”. This is a surface conversion process that hardens the steel’s surface. Unlike a chrome lining that adds variable thickness to the bore, QPQ just hardens the barrel and barrel extension at their current dimensions. This leads to more consistency from one barrel to the next. The use of QPQ on the barrel extension also serves to add lubricity that makes it easier for the bolt to rotate into and out of battery. Reducing the effort to rotate the bolt means the bolt lugs will have a longer life.
BA Performance Series
Moving to the next line that Ballistic Advantage offers is the Performance Series. This series offers the Hanson contour, which is my favorite because it puts steel in the right places without unnecessarily adding weight. The Hanson contour places enough steel between the chamber and gas block to maintain accuracy when hot and then it tapers to a narrower contour between the gas block and the muzzle. The Hanson contour also uses a radius for the area around the gas block instead of 90-degree angles that can negatively impact accuracy.
The Performance Series also uses 4150 CMV steel instead of the regular 4150 Chromoly steel. The difference there is the presence of Vanadium. Vanadium is part of the most durable mil-spec written because Vanadium makes the steel harder and more resistant to wear, while also being more corrosion resistant. If you’ve got a few extra bucks, 4150 CMV is always a good idea for a hard-use barrel.
Additionally, the Performance Series has a nickel boron coated barrel extension and an 11-degree target crown. The nickel boron barrel extension is one of the best applications of the material. It is hard and slippery. When the AR fires, residual chamber pressure pushes the bolt and lugs into the extension’s lug abutments. The bolt carrier moves rearward forcing the bolt to twist and unlock while being pushed against the extension. This is why bolt lugs shear off, especially the ones that straddle the extractor. Coating the extension in nickel boron reduces the friction between the two parts, reducing the stress on the lugs, and prolonging the life of the bolt.
The Premium line has the same nickel boron-coated barrel extension and the 11-degree target crown that creates optimal accuracy, but these barrels are made from stainless steel and have a bead-blasted finish. Stainless steel is a more expensive material that is easier to machine and cut, so the most consistent and accurate barrels usually come from it. Ballistic Advantage offers barrels for AR-15s in 5.56x45mm, .223 Wylde, 6mm ARC, 6.5 Grendel, .300 Blkout, and .350 Legend. Large-frame AR barrels are available in 6.5 Creedmoor and .308 Winchester. Barrels are offered in all of the common lengths, to include the really short ones. All barrels, except for the 9mm models, carry a sub-MOA guarantee.
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