The 6 .8 Remington SPC (6.8x43mm) is a potent alternative to the 5.56 NATO for an AR-15 rifle, especially when you’re planning to use them in shorter barrels. The 6 .8 SPC round was purpose-built from the very beginning to ensure optimal performance in shorter barrels compared to the .223 Remington or 5.56 NATO round. The .223 and 5.56 ammo were designed for 20-inch barrels and are not as popular for close-quarter fighting.
In other words, firing the 6 .8 SPC cartridge will give a better performance from the ubiquitous SBR compared to the 5.56mm from the shorter barrel. In this article, we will be going through some of the best 6 .8 SPC barrels currently on the market.
Why Choose 6.8 SPC?
The 6 .8 SPC is also known as the 6.8mm Remington Special Purpose Cartridge which’s a rimless intermediate cartridge developed by Remington for United States Army Marksmanship Unit as a potential replacement for the 5.56x45mm NATO.
Though it was not able to replace the 5.56, it has found a niche following among civilian shooters who want to get better shooting performance out of their standard AR-15 carbine. The 6.8 SPC offers ballistics in between the 5.56 and larger .308 Winchester round. The 6 .8 SPC round features the same diameter as the .270 Winchester, a very popular hunting around since the 1930s.
The main advantage of the 6 .8 SPC round is that it can deliver superior downrange ballistics compared to 5.56 at longer ranges. Unlike the .308 Winchester, the 6 .8 SPC round can also be fired out of the AR-15 platform without having o switch to a larger and heavier AR-10 platform.
When it comes to specifics, the 6 .8 SPC can offer 44% more energy compared to the 5.56x45mm NATO round at ranges up to a thousand feet to hit targets harder and sustain less bullet drop.
What is the Optimal 6 .8 SPC Barrel Length?
The 6 .8 SPC ammunition was developed in response to objections about the stopping power of the 5.56mm NATO ammo and is aimed to improve the 5.56mm cartridge lethality when fired from the M4 carbine (16-inch barrel). Hence, the 6 .8mm SPC round was conceived mainly for 12” – 16” barrels, currently most familiar in short-barreled rifle (SBR)/carbine platforms.
Though the 5.56 ballistic performance will decrease in the AR-15 platform when you start chopping down the barrel length, the 6 .8 SPC round actually does quite well from shorter barrels considering it was designed for maximum efficiency in short-barreled rifles.
While the performance of the 6 .8 SPC is arguably second to none in an AR pattern service rifle with a 16” barrel, it gains minimum velocity as the barrel length increases. Hence, increasing the barrel length beyond 16 inches might provide a bit of extra power but not enough for most applications to be worth the hassle of doing so.
Benefits of Upgrading your 6 .8 SPC Barrel
The barrel length of the 6 .8 SPC caliber will influence the ballistics performance and hence, your shooting style. Nonetheless, the optimum barrel length will really depend on your own intended use. Testing has found that 16” to 20” barrel lengths will generate about 30fps per inch velocity, depending on loads. So, getting a 20” barrel will be great for long-range precision as it boasts slightly higher velocities and slightly less bullet drop.
On the other hand, those using their SBR or a shorter AR pistol configuration for the vehicle or home defense would prefer the 12.5” barrel length. However, the most popular length of choice for the 6 .8 SPC round is the 16” carbine which provides approximately 85-90% of the 6.8 cartridge’s maximum velocity.
Plus, 16” is also the shortest length legally allowed in most states. It’s also a handy size that will still shoot great groups, making it an ideal weapon for carrying on-foot during both day and night time hog hunts.
Aspects to Consider When Buying New 6.8 SPC Barrels
Considering the fact that the barrel is the crown jewel of any AR-project, you should definitely spend some money to invest in a high-quality 6 .8 SPC AR-15 barrel to expand your shooting capabilities. Here are a few features to look at that would determine the future use of your 6 .8 SPC AR rifle.
The build materials used in the construction of the 6 .8 SPC AR-15 barrel have the most direct impact on the overall quality and longevity of the barrel. It is recommended to opt for stainless steel or titanium as they are very durable, strong, and long-lasting.
Rust Resistant Finish
Since the barrel is constantly exposed to external elements, its structural integrity can become severely weakened if rust and corrosion set in. That’s why you shouldn’t just look at the materials that the barrel is built from, but it should also be coated in rust and corrosion materials such as cerakote or nitride finish.
It is recommended for you to look for a 6 .8 SPC II chamber. This is the corrected version of the original 6.8 SPC to result in better performance and is also readily available for purchase from a large majority of barrel manufacturers.
While the 6 .8 SPC is a multi-purpose rifle, you simply cannot assemble a great shooting AR rifle/carbine without a great barrel. The evolution of the AR-15/M15 barrel ranges from the original lightweight 20” rifle barrel to the most popular profile known today – the 14.6” military M4 barrel.
The original pencil-style, or “A1” barrels were good for snapping off single shots, they’re not the best choice for full-auto shooting. Therefore, the company has developed new 6 .8 SPC barrels called the Special Purpose Rifle (SPR) and Designated Marksman Rifle (DMR) barrel with a barrel length of 18 and 20 inches that are moved toward heavier profiles. One thing to note is that these 6 .8 SPC barrels are not designed for spray and pray type of shooting, but rather for slow, precise, and methodical shooting.
One particularly popular rifle profile that features a 6 .8 SPC II chamber is the 16” stainless steel barrel called the “Recce” or “Recon”. These are massive barrels under the front guard that provide useful thermal mass to absorb a lot of shooting.
There are also other AR barrel profiles available out there and one way to get lighter weight is the vertical cannelure or fluting. This process involves the removal of material from the barrel’s outer surface in grooves that run lengthwise along part of the barrel. Another process to lighten the barrel’s weight is a “dimpling” process that creates a lot of simples along the barrel’s surface. While the fluting makes it lighter, both processes produce better thermal efficiency in shedding heat.
Barrel Twist Rate
The original 5.56 AR-15s have barrels with a 1:14 twist rate, the current M4 carbines offer a twist rate of 1:7. Since the 6 .8 SPC II rifles use bullets weighing between 90 – 110 grains, you should stay away from the 9.5 barrel twist and use the 1:11 twist rate instead.
Review of the Best 6.8 SPC Barrels
Below are some of the best 6 .8 SPC AR-15 barrels in the market today to choose from that best suits your needs and taste.
1. Wilson Combat AR-15 Recon Barrel 6 .8 SPC II
Wilson Combat is a household name among the AR-15 aftermarket industry and the brand name simply screams quality. The most notable examples of high-quality components for a variety of different weapons including the 1911 and AR-15. Their reputation continues to shine with their stainless steel fluted 16” match-grade Recon Tactical barrel that’s designed to handle a range of tasks, including plinking, all-purpose field applications, and hardcore hunting.
Featuring a “Recon” fluted profile, the Wilson barrel enhances rigidity while remaining lightweight. As an added benefit, the 6 .8 SPC barrel’s fluting is also designed to ensure greater cooling for long strings of fire. Aside from that, the Wilson Combat 6.8 Recon 16-inch barrel features a medium contour, 6 .8 SPC match-grade barrel machined with a mid-length gas system, and hand-polished M4-style feed ramps that have all passed and completed rigorous final inspection process.
Overall, these 6 .8 SPC II barrels are proven to be one of the best in the market and sports a precision muzzle crown with ⅝” x 24 muzzle threads and crisp CNC markings. Each Wilson Combat AR-15 Recon barrel even offers a four-groove precision button rifling with a 1:11” twist rate for excellent performance and gilt-edge accuracy for bullet weights between 85 to 115 grains.
You would like this if:
- You want stainless steel 6 .8 SPC II barrels with a 1:11” twist rate.
- You want a match-grade 6 .8 SPC AR-15 barrel with M4-style feed ramps, mid-length gas system, and 5/8×24 threaded muzzle.
- You want a 6 .8 SPC AR-15 barrel with increased surface area to provide better cooling.
You might not like this if:
- You’re shopping with a budget as this 6 .8 SPC barrel might be a bit too pricey for some.
- You want a lightweight 6 .8 SPC AR-15 barrel.
2. Wilson Combat AR-15 Ranger Barrel 6 .8 SPC II
The venerable Wilson Combat released yet another AR rifle series dubbed the ranger that’s been designed as a reliable, easy-to-carry hunting rifle for times when lightweight is a prerequisite. For the AR-15 series, Wilson Combat developed a Ranger match-grade, a tapered barrel that’s available in 14.7” or 16” lengths to suit different calibers.
If you want to build a fast-handling, precision AR carbine, then you’ll need to consider the Wilson Combat Ranger profile barrels as they’re the lightest contour of Wilson AR barrels. The TR68RAMG mil-spec barrel model in 6 .8 SPC II chamber is available with a 16” barrel and weighs less than 27 ounces only, making it one of the lightest ones in the market.
Machined from Type 416R stainless steel, this 6 .8 SPC barrel was created for longevity with a mid-length gas system and a standard .750-inch gas block journal. The Ranger barrel also sports M4-style feed ramps with 5/8×24 threaded muzzles on the barrel top.
The Wilson Combat AR-15 Ranger barrel combines six groove button-rifling with a right hand 1:11” twist rate to deliver exceptional accuracy with standard bullet weights of 90 to 110 grains. In fact, this 6 .8 SPC match-grade barrel delivers extraordinary accuracy for such a light profile and can even out-shoot average shooting mechanics as it keeps sub ½ MOA groups at 100 yards.
Though the Wilson Combat AR-15 6 .8 SPC barrels are made to mil-spec standards, it’s found that there are little to no complaints on final quality control concerning incorrectly cut chambers. In addition to making the rifle easier to carry for long periods of time thanks to its lightweightedness, the 16” Ranger barrel increases speed when transitioning between targets.
You would like this if:
- You want a matte bead-blasted stainless steel 6 .8 SPC II barrel with a 1:11” twist rate.
- You want a 16” match-grade barrel with M4-style feed ramps, a .750-inch gas-block journal, a mid-length gas system, and 5/8×24” muzzle threads.
- You want a lightweight 6 .8 SPC AR-15 barrel that weighs only 17 ounces.
You might not like this if:
- You want to use your rifle for rapid-fire shooting.
3. Black Hole Weaponry 6 .8 SPC II Barrel in 20-in Stainless Steel
The Black Hole Weaponry was recently acquired by Columbia River Arms, but they’ve continued to make custom rifle barrels using state-of-the-art technology. So, the BHW/CRA barrels offer excellent value for creating substantial accuracy improvements in your standard AR.
Made from match-grade 416R stainless steel with a Rockwell 27, the Black Hole Weaponry barrel features a polygonal twist rifling that’s typically found in Glock and H&K firearms. However, unlike the traditional sharp-edged lands and grooves, this barrel has an arc-shaped rifling that offers gentle hill and valley forms to add accuracy, reduced gas cutting, increased velocity, and even ease of cleaning.
The 6 .8 SPC BHW 20-inch barrel features a Caudle 3 land polygonal rifling with 1:11 twist rifling. Unlike the five-groove rifling, the three-groove polygonal rifling is more of a match style rifling suitable for longer barrel precision weapons where accuracy is a must.
The AR15-6.8SPC-1×11-20-CON Black Hole Weaponry barrel is a highly configurable option in terms of fluting options and contours. In fact, this particular 20-inch hBAR barrel comes with the recommended rifle-length gas system, Bull profile, and straight fluting that will provide heavy barrel accuracy with good heat management, especially when paired with ⅝”x24 muzzle threads.
Other than that, the custom rifle barrels have also passed stringent magnetic particle inspections (MPI) and further non-destructive testing to ensure the integrity of each barrel. Though this 6 .8 AR-15 SPC barrel might take a while to break-in, it is still one of the best barrel upgrades that’s capable of holding accuracy during sustained fire.
You would like this if:
- You want a 6 .8 SPC rifle barrel that’s made from 416R stainless steel with matte black finishing.
- You want 1:11” polygonal three grooves rifling with 5/8×24” threading and M4 feed ramp.
- You prefer 6 .8 SPC AR-15 barrels that have passed MPI (magnetic participle inspections) for better integrity.
You might not like this if:
- You’re shopping with a budget as this 6 .8 SPC AR-15 barrel might be a bit too pricey for some.
4. Wilson Combat Match Grade Barrel, 6 .8 SPC II Recon SR Tactical
Yet another one from Wilson Combat, this is one of the best 6 .8 SPC barrels available for those who wish to build their own general-purpose rifle that’s well-equipped for hunting, home defense, or tactical competition. The Wilson Combat Recon Tactical Profile 14.7” barrel offers over 40 different variations of barrels in six popular chamberings. With the Recon configuration, your 6 .8 SPC AR will swing easily and quickly without sacrificing any accuracy, perfect for tactical shooting.
This Wilson Combat 6.8 SPC barrel is a medium-weight, 14.7-inch match-grade barrel that’s made from 416R rifle rated stainless steel to be ideal for a high rate of fire. While the Tactical-Recon 6.8 SPC barrel features a hand-polished bore and M4-style feed ramps, the barrel’s machining and precision button rifling are absolutely flawless to provide superb accuracy with 0.5-inch groups.
Representing “Suppressor-Ready”, the SR muzzle features 5/8×24-TPI-threading that optimizes the build of your AR platform to accept flash hider/sound suppressors. Other than the “Suppressor-Ready” feature, the Wilson Combat 6 .8 SPC 14.7” SR barrels are great for non-suppressed applications.
You should ensure your 6 .8 SPC barrel meets the 16” minimum length requirement for legal rifle ownership to avoid the short-barreled rifle (SBR) configuration and to stay away from registering the carbine as an NFA weapon. You may also consider permanently attaching a muzzle brake/flash hider of sufficient length to bring the barrel length up to 16 inches.
The bottom line is that the Wilson Combat Recon SR 14.7” delivers precision accuracy in a small package for custom AR rifle projects. Installation of the 14.7” barrel in your build rifle is great for CQB circumstances with the ability to permanently attach flash hider or muzzle brake to maintain a handy, optimized size without sacrificing any reliability.
You would like this if:
- You want a match-grade 416R stainless steel barrel with a matte bead-blasted finish.
- You want a short 14.7” barrel with a 1:11” twist rate with precision button rifling.
- You want the best 6 .8 SPC barrel that features 4-style feed ramps, ⅝-25 muzzle threads, and a mid-length gas system.
- You want a 6.8 SPC barrel that’s suppressor-ready.
You might not like this if:
- You don’t want to permanently attach a muzzle device for it to be NFA legal.
Many AR aficionados are building a number of high-end AR projects designed to meet a number of different tasks focused. However, it is undeniable that the heart of every project would be to get a match-grade barrel to gain the most significant benefits.
Regardless of whether you are planning to use your 6 .8 SPC chambered AR-15 as a practical, all-round AR rifle or as a Designated Marksman Rifle (DMR), these missions demand a compromise between handling and weight for carrying, as well as to take muzzle velocity and heat absorption into consideration for optimum accuracy.
Hello there, it’s Michael here. A gun lover since young, served the country for the last 20 years. I started the blog to share my experience and gun-related knowledge accumulated throughout the years. Hopefully, you will find something useful over here or just have fun! You can learn more about me here.