The AR platform has been long dominating the rifle market today and with good reasons too. The choices for customizing your AR are endless. Shifting the caliber of your rifle to another mid-range cartridge, like the impressive 6.8 SPC, usually needs changing only the barrel and bolt.
Otherwise, you can build your 6.8 SPC upper from the ground up. This gives you the chance to work out some gunsmithing skills and get exactly the rifle you want. Here, we review some of the great stripped-down uppers for your 6.8 SPC build, in hope that you know which is the best 6.8 SPC uppers for you.
Perks of Upgrading to the 6.8 SPC Upper
The 6.8 SPC upper receiver was developed at the start of the 21st century by Remington Arms and the US Army Marksmanship Unit. It was meant as a possible upgrade to the 5.56x45mm NATO.
Although the 6.8 SPC does show some outstanding performance, the military has yet to settle down on a replacement for the 5.56mm upper receiver. Using experience gained from the Iraq War, the 6.8 upper receiver was engineered for improved performance in urban combat with a short-barrelled carbine.
The 6.8 is a co-operation between the unsurpassed external ballistics of the 6.5mm upper receiver and the excellent terminal ballistics of the 7mm upper receiver. What this summarises down to is that the 6.8 upper receiver offers stopping power somewhere between the 5.56 upper receiver and the venerable 7.62 NATO upper receiver.
It does this while remaining compatible with standard AR-15 lowers. While upper receiver logistics are only slightly impacted, with a 25 round, 6.8mm magazine being the same size as a 30 round 5.56mm upper receiver one.
Another advantage is that the 6.8 upper receiver is pretty inexpensive and widely available. The upper receiver was not as affected by the 2013 ammo shortage as the current and former US military rounds that are popular with the tactical crowd. It is also very easy to develop sub-MOA 6.8 rounds by hand-loading for your rifle’s unique barrel harmonics.
Features of Getting the Most Fitting Uppers
The best 6.8 SPC upper receivers will fit with any mil-spec AR-15 lower with little to no problems. On top of that, here are a few upper receiver features to look out for on a stripped-down upper and a few of the choices of great uppers.
First off, decide whether you’re going full-featured 6.8 SPC upper receiver or lightweight upper receiver. We all have general ideas about the intended purpose of our prospective firearm.
From hunting to plinking to shooting competitions, these upper receiver ideas usually don’t pan out. Maybe we don’t get around to realizing some use cases, we will hit on brand new ideas of what to do with our weapon.
Perhaps it’s best to stick to a general, adaptable design philosophy and take it from there. Fortunately, the AR upper receiver is nothing if not adaptable.
One common feature of the best 6.8 SPC uppers is a forward assist. This is an upper receiver plunger on the right side of the rifle used to force wedged rounds into the chamber. This has been a default feature on most ARs, particularly the AR-15 in this case, for a few decades now, but opting out is an option if you wish to save some weight.
The same can be said of upper receiver dust covers, although we’d strongly advise having one to maintain the reliability and durability of your receiver. The advantage of getting an upper without a dust cover is that it gives you the choice of separately choosing exactly which upper receiver dust cover you want.
Modern uppers generally come with almost nothing but a Picatinny rail on top. No carrying handle and no sights at all. Carrying handles went the way of the flintlock a long time ago. Sights are such a substance of personal taste uppers that including them with an upper will almost be an offense.
Finally, you will want an upper construct of pulverised or forged aluminum finished or coated for durability. M4-type feed ramps are your best choices for uppers, but only if the barrel extension you choose also has them. These feed ramps help the 6.8 SPC caliber feed without much problems.
How to Install an Uppers
Assembling a 6.8 SPC upper, or any AR platform upper, in this case it is the AR-15 platform, is pretty much straightforward. The entire process only takes approximately five to ten minutes. AR multi-tools are also readily available. These are usually for tightening the barrel nut and the handguard cap.
Just follow these step-by-step instructions to properly install your barrel, gas block, handguard, suppressor, charging handle, and bolt carrier group to your 6.8 SPC upper.
- Secure the 6.8 SPC upper in a vice. Insert the barrel right into the barrel opening using enough force to get it snug. Make sure to be careful to get the alignment notch on the barrel into the groove on the upper.
- Thread the barrel nut on. Use a barrel nut tool to tighten the barrel nut as much as you can. Be careful to align the hole in the barrel nut with the hole in the complete upper to accommodate the gas tube.
- Slip your gas block tube through the hole in the barrel nut while aligning the block to the gas hole on the barrel. The gas block is secured to the barrel with a varying number of screws. Loctite is recommended.
- The handguard (or forend grip) goes over the barrel and threads onto the barrel nut. As soon as the handguard is on as tight as possible and properly aligned with the top of the upper, tighten the tension nut to hold it in place. Two anti-rotation screws, one both sides, also help hold it in place. Use a special AR tool to make tight the handguard cap.
- Thread your flash suppressor on, making sure that no slit faces directly downward.
- Place your charging handle into the hole in the back of the 6.8 SPC upper where the bolt goes. You will feel a location on top of the opening made to fit the wings on the charging handle into. Slip it in and it will move into place.
- Extend the bolt from the bolt carrier group, it will not slide into the receiver otherwise. Fit the gas key on the carrier group into the underside of the charging handle and simply drop the bolt carrier group into the high-quality complete upper.
The steps above will provide you a general outline of the quick and easy process of assembling your 6.8 SPC upper. However, assembling components based on text instructions alone isn’t always entirely straightforward. Make sure that you have the components and the tools listed above. Note that high-quality flash suppressor isn’t an important component.
Review of the Best 6.8 SPC Uppers
Below we outline some of the best 6.8 SPC uppers available today. Both are stripped-down, which means you are free to opt for the best high-quality barrel, charging handle, bolt carrier group, and other components.
1. Aero Precision AR-15 Stripped Upper with Marking (No Forward Assist)
This is a very reliable, no-nonsense 6.8 SPC upper, engineered from 7075-T6 forged aluminum and anodized black. Without a forward assist, this upper has a classic, sleek look, saves some weight, and cuts down on moving parts that can possibly fail. M4 feed ramps cut down on the requirement for a forward assist, especially if you don’t expect to be using your rifle in a prolonged, life-or-death black gunfight.
This upper has been precision-machined to mil-spec M4 standards and class. This makes sure that the broadest compatibility with other components. This is particularly relevant to the dust guard. Make sure that you choose one that is also 100% mil-spec. This upper is not only compatible with 6.8 SPC, but with 8 other caliber manufacturers too.
The Picatinny rail manufacturer has laser-engraved T-marks to make sure that you reattach your sights or other components in precisely the same position. This is vital to maintaining accuracy.
This is an extremely popular 6.8 SPC upper that enjoys a flawless level of customer satisfaction. If weight or a slick, classic look are of fully high significance, you can’t go wrong with this upper. It has a lifetime warranty and features incomparable compatibility with other components and other calibers.
This makes the Aero Precision a great base on which to experiment with other component choices. You can always use it for your next AR build, maybe in another caliber, if at some point down the road you choose to switch to another upper for your rifle. With all the little particulars looked after, however, fully including the M4 feed ramps and the T-marks on the rail, why would you need to upgrade at all?
2. Bravo Company – AR-15 or M4 Flattop Upper Receiver Assembly
This upper is also engineered from 7075 aluminum and hard-coat anodized. Everything about this upper from the milling to the anodization meets mil-spec standards. The interior bore even comes with a mil-spec dry film lube to fully reduce wear.
The Picatinny rail comes with T-marks to ensure sights and other components are remounted in the correct places. Internally, you’ll find M4 feed ramps which can make a huge difference in feeding. This upper is compatible with 5 different calibers, including the 6.8 SPC. Unlike the Aero Precision, this upper comes pre-assembled with a related forward assist and fully dust cover option.
The forward assist pawl (the plunger or button) is made of heat-treated tool steel. One feature to look out for is that the dimensions of the socket where the barrel extension fits are made to the tightest possible tolerances. This is a design feature that ensures greater accuracy. Some users have failed to fit their barrels in and blamed it on the upper. As a matter of fact, all they had to do is to warm up the aluminum with a hairdryer for temporary expansion.
This 6.8 SPC provides some of the most scrupulous mil-spec adherence you are able to find. This ensures compatibility with the great middle-of-the-road of other AR components. With the lifetime warranty, you can’t possibly go wrong. The M4 feed ramps are an important feature with the 6.8 especially, helping it feed reliably.
Top of the line mil-spec finishes, both inside and out, assistance make this one of the most reliable uppers your money can buy. Don’t be surprised if fitting the barrel is a challenge. Don’t lap or file anything, all you need to do is to apply a bit of heat to the aluminum. You’ll appreciate the accuracy of the tight fit of a variety of different crops.
3. Palmetto State Armory Mid-Length 6.8 SPC II Upper With Barrel
First of all, this is not just the barrel itself but actually a comprehensive, mid-length 6.8 SPC upper. The expediency here is that as you put together all of the pieces you need for your new 6.8 SPC AR-15, you can get the entire upper receiver in a single package so you don’t have to buy and assemble everything a variety of different separately yourself.
The barrel that comes with this mid-length upper receiver, however, measures eighteen inches long and is engineered out of 416R stainless steel. This is a very rust and corrosion-resistant metal as we may have mentioned about previously, and it’s also quite durable. The barrel also comes with a twist rate of 1:11, which is great for the 6.8 SPC in order to optimise performance. It comes with an A2 style flash hider too.
All in all, the PSA Mid-Length 6.8 SPC Upper with the 416R stainless steel barrel is a great choice if you need a complete 6.8 SPC upper receiver for the 6.8 SPC along with a good barrel to pair with it. For obvious reasons, if you only want the barrel, you can always just take the barrel itself when you buy the package and then place all of the other components in a storage area.
4. Barrett Firearms MFG INC – Barrett AR-15 30RD Magazine 6.8 SPC
This is a very high-quality full-steel construction that can fit any AR-type rifle that chambers the 6.8 SPC round. Impressively, it all provides you with a very sparing 30 round capacity, which you will usually expect with a standard mil-spec rounds magazine. So this is a tall capacity 6.8mm Remington SPC magazine to shoot deer.
In addition to it, the magazine is specifically coated in Teflon, making it scratch-resistant as well as helping in the smooth seating of the magazine. Furthermore, there is a polymer follower built-in so that the rounds are fed into the rifle fluidly without many issues.
This is a semi-automatic magazine that can chamber the Remington rounds for hard-hitting targets. So whether you are going for a competition shooting time, hunting, or using this magazine in real combat situations – you’ll have a powerful piece of kit. Furthermore, you’ll be glad to know that the magazine is made in the USA, meaning that the quality standards of production will be quite good.
Last but not least, another interesting fact about this magazine is that it can also hold the 224 Valkyrie rounds. These are .22 caliber rounds that are bottlenecked and rimless. These rounds are specifically great for auto-loading AR-style weapons, and can even be used in bolt-action rifles too.
If you are looking for an AR with more firepower than the 5.56mm, the 6.8 SPC is a great choice to go for. Both of these uppers are great choices to build your 6.8 rifles on. The Aero Performance is a bit sleeker, more classic, and lighter in weight.
The Bravo Company is full-featured and offers the durability of being rigorously mil-spec. Building your own 6.8 SPC is a great way to make the perfect gun for you and pick up some knowledge and skills along the way.
Frequently Asked Questions (FAQs)
Q: Why Do You Need A 6.8 SPC Upper?
If you are looking to have an AR-15 chambered in 6.8 SPC, then you will need a 6.8 SPC upper. But why would you want to go with 6.8 SPC for your rifle though?
The 6.8 SPC was developed at the beginning of the 2000s in a partnership program between the United States Army marksmanship unit and Remington Arms. As with most AR-15 calibers, it was engineered as a potential upgrade over the 5.56x45mm NATO and .223 Remington rounds, which have been the standard AR-15 rounds for many decades.
The 6.8 SPC has never replaced the 5.56, but it still offers much better ballistics. It has more energy, more stopping power, better accuracy, and greater effective range. With the 6.8 SPC and a quality 6.8 SPC barrel, you can easily reach sub-MOA groupings.
As a matter of fact, the ballistic of the 6.8 SPC competes with the various 6.5mm and 7mm rounds that are currently available on the market as well but in the same size package of a normal AR-15. This means with the 6.8 SPC, you do not require to upgrade to a larger .308 caliber AR-10 rifle.
The 6.8 SPC magazine is also the same size as the 5.56 magazine, and the lowers for the 6.8 SPC and 5.56 AR-15s are almost as identical. The only difference should be the markings on the lower.
When it comes to the upper receiver, there are a few Mil-Spec upper receivers that are workable and companionable with both the 6.8 SPC and the 5.56x45mm NATO. You just need to get a different barrel for your 6.8 SPC. If you already have a 5.56 AR-15, there are only a small number of extra parts you’ll need to get your hands to convert it to 6.8 SPC.
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.