These barrels will have long, shallow sections of removed material, or small circular pieces of material removed from the surface of the barrel. The biggest advantage to these lighter barrels is the decreased weight, which can be crucial if this is a rifle you’ll be carrying for long periods of time.Ĭommon features found on many barrels today are processes used to reduce weight through fluting or dimpling. Some manufacturers will even have proprietary profiles that are engineered to combine some great characteristics of many different contour types. Lighter weight barrels with contour types such as government, gunner, tapered, M4, SOCOM, and Pencil, will be perfect. The vast majority of AR owners will never shoot enough ammunition fast enough to need a heavy barrel in the entire time they own the firearm. These will be the heaviest to carry, but also will heat the slowest, keeping your accuracy truer for longer. Most will have two different thickness radii, with one transition point somewhere in between them. When it comes to selecting which barrel profile is right for you, consider the performance demands you’ll be putting on your rifle.Ī “heavy” barrel, sometimes denoted as an HBAR barrel, will lack the various changes in thickness along the length. That’s the reason behind the extra material at the muzzle end of a M16A2 rifle barrel according to Eric Kincel of Bravo Company USA. Sometimes the answer to the latter question is as simple as “the barrels were bending when soldiers were using them to pry open crates, so we made them thicker on the end.” Seriously. It’s also not always clear why certain profiles or contours are designed the way they are. There are many styles of Barrel contours, or profiles, and a lot of them can appear similar. If you’re building a precision rifle that needs ½ MOA accuracy and will never be subjected to sustained high rates of fire, a stainless steel, unlined barrel may be what you’re looking for. Those who are looking for a barrel that will perform at a high level across the widest number of applications, a 4150 Chrome Moly Vanadium barrel with a chrome or nitrocarburized bore lining will fit the bill. The tradeoff is a lack of protection against corrosion, and shorter barrel life.

This lining is becoming more popular, due to its lack of negative effect on accuracy.įor the most supreme accuracy, an unlined stainless-steel barrel will give the best performance. The nitrocarburizing has the outomce of a chemically altered surface inside the bore of the barrel. More recently, proprietary methods of nitrocarburizing the lining of a barrel have been patented, and these forms of barrel linings will use trademarked names like Melonite, Tenifer, Salt Bath Nitride, and others. Many manufacturers have refined their processes and produce barrels that are highly capable with chrome lining. However, over time, chrome lining can reduce accuracy since the coating unevely wears down the length of the bore. The lining provides a protective coating against corrosion and fouling, which increases the life of the barrel. It can be polished for a distinct look, shot peened for a matte, less vibrant appearance, as well as colored with chemical treatments to feature a dark finish.Ĭhrome lining in the bore of a barrel was seen as a huge breakthrough for reliability when it was first introduced. The hardness ratings of each type are the same, and while each alloy does include chrome, it is not a large enough amount eliminate rust forever.Ĥ16R Stainless Steel is also commonly used in AR barrels and it has more chrome, making it more corrosion resistant. AR barrels are usually made from 4100-grade Chrome Moly steel alloy, most commonly 4140 - which can be cheaper - or 4150 which includes Vanadium in the alloy to increase strength.

7mm-08 tc contender barrels for sale