AR-10 / LR 308 Barrels
The AR-10 is certainly not a new kid on the block. In 1955 the U.S. Army was in the market to replace the beloved M1 Garand as their standard issue rifle. Mr. Eugene Stoner, who was a machinist and the chief engineer for Armalite, designed and created the original version of the AR-10 for submission. The Army considered and ultimately rejected his AR-10 in favor of the M14. In 1957 Mr. Stoner re-designed the AR-10, creating what we know as the AR-15. However, it is the AR-10, its barrel to be specific, that we will look at in this article.
The AR-10 .308 barrel is easily the most determining factor in the accuracy of a weapon. Its profile identifies the type of barrel and determines the type of handguard that you will need, as well as the purpose for which it will be used. There are two important variations of the AR-10 platform that are determining factors for which barrel you need, the regular AR-10 and the DPMS .308.
AR 308 Barrels Are Not One Size Fits All
Because of the militaries reluctance to adopt it, during the decades following its creation the AR-10 kind of fell by the wayside. Many variations of the AR-10 platform were manufactured during its lifetime. It all shook down to basically two versions. The majority of the marketplace is held by the AR-10 version and the DPMS version. While both look the same from afar, they are far from the same, that includes the barrel, which is not interchangeable. One would have to be a professional to tell them apart when mounted on the weapon. However, side by side the DPMS LR 308 barrel is easily distinguished from any AR 308 barrel. If you own the DPMS type of this weapon you will need to purchase an LR 308 barrel. There are external differences between the two platforms if you’re not certain which one you have, find a professional and find out for sure.
Government Profile Barrel
Government profile AR-10 barrels are popular among most shooters for a number of reasons. Shorter range competition, general shooting, and self-defense are among the uses where a government profile AR 308 barrel would be most at home. It can be identified by its diameter, that remains pretty much the same diameter from breech to muzzle. While being large enough to dissipate heat, it remains light enough to not be cumbersome. A government profile AR-10 .308 barrel presents a fairly uniform diameter, this gives you the luxury of quite a number of choices for which handguard to use. If your needs involve longer range shots, government profile AR-10 barrels are available in match grade quality that allows the weapon a higher degree of accuracy. While once considered a luxury, only to be used by serious competitors, now many shooters run match grade barrels.
Heavy Profile Barrel
Long range hunting and long range competition shooting are two situations where you might require a heavy barrel. These AR-10 barrels are not uniform in thickness but begin heavier at the breech, tapering to a more normal diameter at the muzzle. Normally shooters choose the fluted version of the heavy barrel to reduce the overall weight, add strength, and better dissipate heat. The added weight of a heavy barrel means that carrying distance quickly comes into the equation. Most long range shooting is done over a Bipod or shooting bench, therefore, the additional weight helps in holding the weapon steady as well as reduce the felt recoil. Wing Tactical carries the right AR-10 barrel for sale regardless of which of these fit your needs.
Do Barrel Length Matter?
In the earlier days of shooting, rifle barrels ran much longer than today. There are still some shooters that believe a 20-inch barrel is a must for proper performance. Mainly, that was because rifle powders used to require that much barrel length to achieve maximum velocity. Today ammunition has evolved and good results are archived in a shorter barrel. However, because of increased stability added barrel length does come into play when the range increases to the targets.
Consequently, most shooters choose to go with either a 16-inch or 20-inch barrel and either will perform nicely. If your main intention for the weapon is self-defense or quick moving competition, then a 16-inch barrel is the way to go. The increased maneuverability is a benefit in either of these situations. However, if longer range shooting is the goal, moving up to an 18-inch barrel may be in order. Keeping in mind that you will likely add a muzzle device and that will add length to the barrel. The difference in the percentage of powder burnt and maximum velocity attained will be minimal. Honestly, very few of us are Olympic grade shooters, myself included, and will find that either barrel will outperform our abilities. Unless you just love to pour over pages of performance statistics choose the length suitable for your normal shooting situations. Do get quality equipment, and with practice, anyone can improve their performance.
Quality Barrel Steel Material and Finish
Certainly, over the ages, people have fashioned barrels out of many different types of steel, some were good and some not so much. In today's world of handheld weapons, there are two types of steel that are commonly accepted as the industry standard. Depending on the use and personal preference either 416R Stainless Steel or 4150 CMV are the only choices to even consider.
416R Stainless Steel
AR-10 barrels presented in bead blasted 416R Stainless Steel are truly a thing of beauty. Highly polished Stainless is gorgeous, however, it simply doesn’t belong in the field. Its surface is easily scratched and then that polish is marred, it belongs in a case to be seen and not used. The matte finish achieved on a Stainless AR 308 barrel that has been bead blasted is durable, functional, and quite attractive. This finish is applied only to the outside of the barrel, of course, and appears silver-gray. Furthermore, the bead blasted finish gives the added benefit of reducing glare. This is certainly a desired attribute if one is hunting, the sunlight glinting off a barrel could alert game to your presence. If at some later time a different appearance is desired, the matte surface lends itself nicely to the application of many different coatings.
Stainless Steel is usually the choice of high-level competition shooters for several reasons. It is considered to be a superior performer in long-range shooting competition yielding superior accuracy. Stainless Steel has a greater resistance to heat erosion, therefore, one can reasonably expect less barrel throat wear over time due to the improved corrosion resistance of 416R steel. When you combine the properties of 416R Stainless Steel with a heavy profile fluted barrel the odds of long-range accuracy are increased.
Quality AR-10 barrels are machined out of 416R Stainless Steel for a reason. One of the properties of this grade of steel is its machinability, resulting in a very fine finish. There are a number of grades of Stainless, however, 416R gains its popularity by adding Molybdenum. This alloy improves the microstructure of the stainless, as well as improving its corrosion resistance. Some wrongly believe that Stainless Steel will not rust, however, that’s not true. It is actually corrosion resistant and among other properties, 416R does help in that area. Without proper care, even 416R Stainless Steel will degrade and corrode, it is quite durable but not indestructible.
4150 CMVS (Chrome Moly Vanadium Steel)
You will also find high-quality AR-10 barrels made out of 4150 CMVS, which is a high carbon steel. The “50” in 4150 denotes there is approximately 50 % carbon added to the steel creating a stronger alloy. 4150 CMVS also adds an alloy called vanadium, increasing both strength and corrosion resistance. This type of steel is cheaper to manufacture, therefore, you can still have a high-quality AR 308 barrel at a lower cost.
When properly heat treated 4150 CMVS yields a higher tensile strength than its stainless counterpart. With this property, it is considered a better choice for high-volume, automatic firing. Therefore if full-auto rock and roll is in your future then this steel is the proper choice for your AR-10. If good maintenance is observed high-carbon steel can be just as corrosion resistant as stainless, therefore it could be a viable option.
AR-10 barrels made out of 4150 CMVS could be “blued” like a traditional rifle, however, quite often they receive a finish more suitable to harsh conditions, such as QPQ Nitride. The initials QPQ refer to the process in which it receives its finish, Quench, Polish, Quench. This special process creates a special type of nitrocarburizing case hardening. The resulting barrel benefits from increased corrosion resistance and improved fatigue strength. The final quench in the QPQ process creates a layer of iron nitride that is three to four microns thick, leaving a durable black finish. Therefore, the AR 308 barrel is well protected from brush or the stray bump that occasionally comes with use.
Choosing The Right AR 308 Barrel
Just as there is someone for everyone, there is a barrel for everyone. If you’re lucky enough to be a member of a shooting club see what barrel others are running. Ask questions, and think about what the typical requirements you will have of your AR-10. Go ahead and get one, and try it on for a minute. If it doesn’t fit your style you can always post your AR-10 barrel for sale, keep it pristine, good used barrels don’t stick around long. Scroll back up and see the great barrels that Wing Tactical have to offer. If you know what you want then go for it. If you have any questions at all, please do contact the good folks at Wing Tactical for all your shooting needs.