Bravo Company Manufacturing, better known as just BCM, has been at their craft for decades. And throughout their tenure, they’ve become well renowned for crafting some of the industry’s most reliable and utilitarian AR-15 rifle systems and components. And among their vast lineup, their upper receivers stand tall as some of their most sought-after offerings.
BCM uppers are well-known amongst resolute AR enthusiasts. Not only do they boast an incredibly high degree of quality, their plentiful selection of upper receivers ensures that there’s something for everyone. But having multiple options to pick through doesn’t necessarily make choosing just one easy.
It’s easy to fall into the pitfall of “analysis paralysis”—the inability to make a decision—in such situations. This common setback is especially prevalent when you consider all that BCM has to offer, and if you’re new to the platform, seeing their uppers labelled as ‘standard’ or ‘MK2’ can cause even more confusion if you don’t already know what these monickers mean.
So, to make things as easy as possible, we’re going to shine the metaphorical spotlight on BCM’s upper receiver options. More specifically, we’ll be looking at their standard and MK2 upper receivers and breaking down what exactly makes them so alluring.
BCM Upper Receivers
BCM offers a lot of different upper receivers, and just like their lowers—which we cover in-depth in our BCM Lower Receiver Guide—they’re separated into two categories: standard and MK2.
BCM Standard Uppers
BCM’s standard upper receivers are just that, their base-model configurations. But what exactly does this entail? Well, much like their other products, BCM’s uppers are carefully constructed to offer nothing short of rugged reliability. All the upper parts that go into their standard upper receivers are made from top-tier materials and have been engineered to offer the most in terms of durability.
Remember, this is BCM we’re talking about, and their standard options come packed with premium features. The upper receiver is made of forged 7075-T6 aluminum, making it exceptionally light and durable, and to bolster its corrosion resistance, it has a mil-spec hard anodized finish. Plus, for easy optic mounting, while the railed section of the upper is T-marked for proper positioning. Additionally, they come outfitted with very high-quality barrels made from certified mil-spec MIL-B-11595E steel. And to round them out, they can come equipped with a wide variety of handguards and muzzle devices.
Overall, despite being BCM’s standard upper offering, they’re a high performer. Being available in so many configurations, they can easily be adapted to fit multiple roles and applications, so regardless of what you plan to use it for, they’re ready for just about anything. And, since they use a mil-spec design, they’re compatible with nearly all aftermarket AR components, allowing you to easily tailor your rifle to best fit your needs.
BCM MK2 Uppers
BCM set the bar high with their standard upper receivers, but they pushed the boundaries again with their MK2 (Mark 2) upper receiver design. The MK2 upper design refreshes the traditional AR-15 upper design, improving its overall durability and performance. As such, MK2 uppers have a few noticeable differences when compared to mil-spec uppers.
Notably, MK2 uppers have added reinforcement around the ejection port and forward assist to offer better structural support. Internally, they have specialized ventilation channels for redirecting excess gas out and away from your face—something that’s especially beneficial when shooting your rifle suppressed. Lastly, though a more minute change, the forward assist is smaller and positioned slightly forward, freeing up a lot of space near the charging handle, giving you easier access to it.
Despite it straying from you the standardization established with AR-15’s original design, the MK2 series from BCM has some serious advantages. It’s still compatible with nearly every standard AR upper component too, except for the forward assist, of course. With that in mind, they can be an excellent pick for anyone looking to build a more durable rifle.
Which is Best?
Ultimately, it’s impossible to declare either one as the ‘best’ option, as both are an exceptional possibility for most applications. That said, if you plan to run a suppressor on your rifle, or simply want some added durability, BCM’s MK2 upper receivers are where it’s at. While you can still adequately run a suppressor with one of BCM’s standard uppers, you’ll need to either run a flow-through suppressor or have specialized parts like a gas-busting charging handle and adjustable gas block for finer tuning and gas deflection. This doesn’t mean that you should immediately disregard their standard uppers though.
For a first-time rifle build, or for those who prefer the simplicity of the mil-spec design, they’re an excellent pick. At the end of the day, choosing one is a matter of personal preference. And so long as you take time to evaluate what works best for you, you’ll pick the right one.
Barrel Length and Use Cases
Regardless of which one you decide to go with, you have plenty of options to choose from, as both upper variants are available in a wide range of barrel lengths, and it’s critical that you pick the right one.
The upper receiver of your AR-15 plays a vital role in determining how it performs in different applications, and the length of barrel is the deciding factor in most cases. So regardless of whether you decide to go for one of BCM’s standard uppers or one of their MK2 options, knowing how different barrel lengths perform is imperative to making sure your rifle functions the way you want it to.
11.5 and 12.5 Uppers
As far as compact 5.56 NATO ARs go, there aren’t many barrel lengths that offer the same level of performance as 11.5- and 12.5-inch barrels. Although there have been plenty of rifle systems fielded in the past that have used even shorter barrels, such as the MK18 CQBR with its 10.3-inch barrel, the performance of 11.5- and 12.5-inch barrels is incredible. Plus, they’re more readily available from BCM.
11.5 and 12.5 barrels have become some of the most popular amongst enthusiasts in recent years. They offer solid performance across a multitude of applications and are compact enough to be effective for close quarters use, putting them in the sweet spot that offers good muzzle velocity and a shorter overall length. With them being so popular, it’s no surprise that BCM offers an assortment of uppers in these lengths.
The Standard Carbine Upper Receiver Group – MCMR-10 Handguard – 11.5 is one of the more popular compact uppers offered by BCM. They come equipped with some exceptionally durable components, including a chrome-lined barrel made from MIL-B-11595E steel, a mil-spec BCG, and an A2 flash hider. However, being an assembled upper, it also comes equipped with the venerable MCMR M-LOK handguard. Lightweight and durable, the MCMR is a great handguard for any AR-15 build and this this upper comes with the 10-inch variant, providing you with plenty of accessory space.
Another great pick is the MK2 Carbine Barreled Upper 12.5. As its name suggests, this upper comes equipped with a 12.5-inch barrel and makes use of BCMs MK2 upper receiver design. This upper receiver is built similarly to the standard 11.5 upper mentioned above—it comes standard with an A2 flash hider, an MCMR-10 handguard, and a chrome lined barrel with a phosphate coating. In addition to the barrel being longer, it also sports a thicker Government profile barrel, and since it’s a part of BCM’s MK2 line, it has all the MK2 upgrades highlighted above. Overall, it’s a solid pick if you plan to run your rifle suppressed or just want some extra muzzle velocity.
Before you set off to build a compact rifle, it is imperative to understand the law regarding rifle classification. For a rifle to be classified as such, it must have a minimum barrel length of 16 inches, anything shorter than that will classify your AR-15 as a Short-Barreled Rifle (SBR), which requires a tax stamp and ATF approval to own. Now, you can also build an AR pistol, but there are additional legal requirements there to consider. Fear not though, for we cover this topic in detail in our AR Pistol Buyer’s Guide—if you’re intent on building a shorter AR-15, we highly recommend giving it a read before doing so.
14.5 Uppers
14.5 upper receivers are easily some of the most popular ones available, and for multiple reasons. They’re one of the best general-purpose upper receiver lengths for the AR-15—the barrel is long enough to have an effective range of around 500 yards with standard 55 and 62 grain ammo, and it’s compact enough to still be maneuverable. That said, with 14.5 inches being just shy of 16, a 14.5 AR would be SBR, right? Well, not necessarily. By pinning and welding a long enough muzzle device to the barrel, the overall length of the barrel can be extended since the muzzle device would be a permanent part of the barrel.
As such, 14.5 uppers are highly sought-after, as they effectively give you a more compact rifle system while keeping up with the ATF’s minimum barrel length requirement. And because of their popularity, BCM offers several 14.5 upper receivers that already come pre-equipped with a pinned and welded muzzle device.
A popular pick is their Standard 5.56 NATO Barreled Upper Receiver – FDE MCMR-13 – 14.5. It comes equipped with a durable mil-spec steel barrel that’s chrome lined and has a government profile, a pinned and welded A2-style flash hider, and a mil-spec BCG. And while this comes with a 13-inch MCMR M-LOK handguard, this upper is available in FDE, adding a nice aesthetic flare to your rifle. And, instead of a carbine length gas system, it has a mid-length one, allowing for a softer recoil impulse.
They also offer the MK2 Mid-Length Barreled Upper 14.5 as well. Coming with the MK2 upper receiver and all its upgrades, this upper receiver makes use of the same overall design as the standard BCM 14.5 option. That said, instead of an FDE handguard, it comes with a black 13-inch MCMR handguard.
16-inch Uppers
The 16-inch upper length is considered by many to be the standard AR-15 barrel length. Meeting the ATF’s minimum rifle barrel length requirement, it’s easy to see why they’re one of the most common upper receiver lengths available on the market. Compared to SBR-length and even pinned and welded uppers, 16-inch uppers lack the same “cool-factor” since they’re so common, but it’d be a shame to overlook them entirely. 16-inch ARs are some of the best do-all rifles, offering more muzzle velocity than 14.5-inch rifles, while remaining relatively compact.
Among BCM’s upper lineup, they have a plethora of 16-inch variants to choose from. As far as their mil-spec options go, BCM’s Standard 5.56 NATO Barreled Upper Receiver with FDE Handguard – 16 is an excellent contender for a GPR (General-Purpose Rifle) build. Essentially, it’s the same upper as the 14.5 option above, just with a longer barrel. It keeps the same FDE MCMR-13 rail and comes standard with a mid-length gas system. But, unlike the 14.5 upper, the muzzle device isn’t permanently affixed to the barrel; so, if you wanted to swap the A2 flash hider for another one later, you could do so with no issues.
Lastly, as you may have suspected, BCM offers several MK2 upper receivers complete with 16-inch barrels. Notably, the MK2 5.56 NATO Mid-Length AR-15 Barreled Upper 16 is one of BCM’s top models. Coming with MK2 receiver upgrades, this one comes equipped with a longer 15.5-inch MCMR M-LOK handguard, giving you even more space for accessories. And like the rest of their uppers, it comes standard with mil-spec BCG and an A2 flash hider, so all you need is a charging handle and an optic, and you’ll be ready to go.
Conclusion
BCM will forever be one of the most widely recognized names in the firearm industry. Their drive to craft high-quality rifle systems, parts, and accessories has been recognized by countless enthusiasts, as well as both Military and Law Enforcement agencies too—and this same commitment to excellence extends to everything they offer, including their uppers.
Whether you’ve already been in the game for a while or if this is your first rifle build, you can’t go wrong when choosing BCM for your next upper. The breadth of their offerings ensures that there’s something for everyone. If you’re a fan of the rugged simplicity that stems from the mil-spec design, their standard uppers can’t be beat. But, if you want something that’s a little more premium, and is better designed for dedicated suppressed use while boasting some added durability, the MK2 series is where it’s at.
Ultimately, choosing between the two is a matter of deciding which one is best for your needs and preferences. But no matter which one you go with, you can rest assured that you’ll end up with a rifle that’s ready to handle anything you can throw at it.
