BCM® Standard 20" Government Profile Upper Receiver Group

MSRP: $620.40
Your Price: $510.40
(You save $110.00 )
(110 reviews) Write a Review
M4 Feed Ramp Barrel Extension
M4 Feed Ramp Flat Top Receiver
T-Marked Upper Receivers
USGI 1/7 Twist Rates
USGI 5.56 NATO Chambers
Mil-Spec 11595E - Certified Barrel Steel (CMV)
5.56 NATO
Barrel Length:
Barrel Style:
Barrel Profile:
Stock Status:

PLEASE NOTE: These batches can sell out quickly.
If the Stock Status is Out of Stock and you would like to get notification when more product arrives, please click the "Email me when Back-In-Stock" link under the Add To Cart button. You will get immediate notification of all new arrivals of product.
If you get a email notification and you check back again with our website to see that the product has already again sold out, please click the link again and add your email to the notification list.
Please check back with our website often, we can not take pre-orders or backorders on these products.
Professional Grade Weaponry, by BCM®™
Made by Bravo Company MFG, Inc. (BCM®™) These Barreled Upper Receiver Groups are designed for shooting professionals with the Mil-Spec features for the demands of their duty. They are fully assembled, headspaced, and test fired.
As a note: BCM®™ barrel components are parkerized separately before assembly. Prior to shipping, all BCM®™ upper receiver groups are test fired for function, laser bore sighted with a Milspec carry handle for sight alignment within Mil-Specs, and then batch samples are test fired for accuracy. As such, the upper receiver group will show handling marks consistent with these quality control procedures.
M4 Feed Ramp Barrel Extension (USGI)
M4 Feed Ramp Flat Top Receiver
In developing the USGI M4 carbine as one of the primary weapons for today s infantry, some modifications were performed to the original M16 platform to enhance the reliability of the shorter barreled carbines. With the shorter carbine gas system and the increased gas port pressure, the carbine cycled faster, and at times the cycle rate could be faster than the magazine would feed ammunition. One of the modifications done to increase reliable feeding included enhancing the angle and the length of the feed ramps. This USGI modification was done to both the barrel extension and the upper receiver, creating a longer and steeper feed ramp. These Mil-Spec M4 feed ramps are part of the original CNC manufacturing process. As a result, the factory machined M4 feed ramps on the receiver are hard coat anodized which adds significant strength to the aluminum. This feature is offered on all BCM® uppers and all BCM® barrels.
T-Marked Upper Receiver
The contemporary M16/M4 rifle is built around the concept of modularity. All of the BCM® flat top uppers feature a USGI type laser etched T-marks to provide addressing for the remounting of tactical accessories such as optics, laser sights, etc. This enables the weapon platform to be easily configured and then accurately reconfigured for each specific mission.
USGI 1/7 Twist Rate
The USGI 1/7 twist rate of all of the BCM® barrels is the preferred twist rate by most professional infantryman. This twist rate has proven very versatile and can effectively run the new heavier 5.56 ammo that is hugely popular with military and private security personal for its superior ballistics.
Mil-Spec 11595E - Barrel Steel
BCM® barrel steel is Mil-Spec per MIL-B-11595E. This grade (CMV) of steel is a Mil-Spec steel used in the USGI M16 family of rifles; it is stronger and will last longer than the typical barrels offered in the commercial market. The Mil-Spec grade steel gets its additional strength and rigidity from an increase in carbon and/or vanadium in the alloy. This will offer increased barrel life and performance through use in all types of extreme environments and temperatures.
Chrome Bore and Chamber
One of the first modifications that were made to the original M16 in the mid 1960 s was the addition of the chrome lined bore and chamber. It is now a worldwide standard in the industry for a battle rifle. The chrome bore and chamber is harder than the barrel steel and on the USGI M16/M4 rifles will aid in chambering, extraction, and reliability. It increases velocity, and also resist against fouling and corrosion from extended use in the field. This gives the end user a longer barrel life with less required time in maintenance and cleaning.
Manganese Phosphate Barrel Finish
Barrels are parkerized with the manganese phosphate finish (Mil-Spec A-A-59267). Military specifications also state that the entire barrel surface is phosphate finished to create a porous surface to absorb oil as to resist against corrosion from the elements. BCM® barrels are phosphated before installation of front sights. This is a much more extensive assembly operation, but insures that the entire barrel is finished and protected . . .even under the front sight base.
5.56 NATO Chambers
The USGI 5.56 NATO chamber is the best choice for effective deployment, reliability, and compatibility, of higher chamber pressures of military ammo.
Mil-Spec F-Marked Forged Front Sight Bases
Mil-Spec for rifles issued to the troops require taller front sight bases on all flat top AR rifles. Many commercial offerings use M16A2 height front sight bases on all of their barrels regardless of what type of upper it is installed on. As a result, owners of rifles and carbines with the flat top receiver configuration can have problems getting a proper 'zero' for elevation with Mil-Spec back up iron sights. As all of the BCM® uppers are built for flat top uppers, all have the proper Mil-Spec F marked front sight base to insure the correct height for iron sight zeroing when using military iron sights. Mil-Spec taper pins secure the forged front sight base with the sling swivel secured by tubular rivets.
Government Barrel Profiles
Duty rifles are built to be carried - day in and day out. The USGI barrel profiles (often referred to as the Government Profile) enable the operator to carry their weapon for longer periods of time and deploy them faster than the heavier commercial H-Barrel counterparts. The government profile barrel is also compatible with the current M203 mounting systems.
HPT / MP Inspected Barrels
Military specifications require that barrels undergo a HPT (High-Pressure Test) load as a part of quality assurance procedures. Commonly referred to as a proof load, the M197 HPT is rated for 70,000 psi. BCM® barrels are proof loaded and then MPI (Magnetic Particle Inspected) to detect any possible flaws in the barrels surface. The barrels are MP inspected with both circular and longitudinal magnetic fields per ASTME1444-01 (current Mil-Spec) to assure a high quality finished product. All BCM® barrels are marked HP MP as our proof load marking.
Copyright © 2005 - 2009 Bravo Company MFG, Inc.
***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit www.p65warnings.ca.gov.***

110 Reviews

  • 5
    BCM 20” gov upper receiver

    Received this upper to do an A4 style rifle. Order was shipped in a fast and professional manner. Previous BCM products have encouraged me to continue to shop with them during an over saturated AR market.

  • 5

    This is my first BCM purchase and I'll definitely be back to round out a couple more lowers. The fit and finish of the product is excellent. As an added bonus, BCM shipped this upper coated in the best smelling oil I've ever had the privilege of sniffing. You'll think I'm crazy, until you open a BCM box.

  • 5
    Customer review

    Got this upper with a carry handle sight, mounted it and took to the range. Couldn't believe at mechanical zero it was dead on, no adjustments needed. Had this on a carbine lower and still cycled fine, still waiting on an A2 stock I ordered

  • 5
    Best pre-made upper I've ever found!

    I now understand the BCM hype, this upper was really put together with care. The front sight post was spot on, took out to the range for some serious break in time... I did not have to make any adjustments to sight in. Put a carry handle on set at z25 and bam! In the bull. Took it out to 100 with the Trijicon and easily was well inside an inch and a half with standard 62gr surplus. Fit and finish are flawless. There is no way to getter a better upper in this price range. My A4 clone turned out great, no better than great! My hat is off to the BCM crew.

  • 5
    Top of the line product.

    Not much to say, top notch quality through and through. BCM is the best, hands down. Don’t cheap out, just save more and get BCM, trust me.

  • 5
    Smooth as silk and flawless function

    All I lack to complete my M16A4 build (first build) is a BCG, CH and rear sight but I just couldn't wait so I slapped in a buddy's BCG and CH and did a 10 round function test and was blown away by the utter lack of recoil. It was my first time shooting a rifle length upper and I also noticed it was WAY quieter than my buddy's carbine. Im very impressed with this upper. I can't wait to get the last 3 components and see just how accurate it is. Im very glad I saved up and spent the extra $ on BCM. I'm now a loyal customer for life.

  • 5

    I wasn’t sure what to expect I had purchased a cheaper upper with a different company and I was so disappointed. I paid the extra cash to bravo Company and wow I was amazed at the quality and accuracy at the range this uppper has given me it is worth every Dollar spent thank you bravo Company

  • 5
    Very well made. Very high quality for milspec gear

    The complete 20” gov’t profile upper and BCM BCG was everything they said it would be. Shooting M855 ball, on a standard M16A2/A4 25/300 meter target set up at 25 meters, it shot 2 to 3 MOA with iron sights, and about 1.75 to 2 MOA with a 4x32 ACOG. Still have to confirm at 300 meters actual, but I expect decent results for a “mil spec” rifle. I used a Spike’s forged lower, a Rock River A2 stock, and the KAC M5 RAS handguard. I will be exchanging the A2 birdcage flash hider for one that will accommodate a suppressor. Otherwise, I was trying to build my version of a tribute to a great rifle - the M16A4.

  • 5
    buy it , not much better avalible

    shipping is quite fast , price is hard to beats