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. These do not include bolt carrier groups or charging handles.

 

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 consistant with these quality control procedures.

This BCM stripped barrel is machined from a 410 stainless steel. It features hand lapped button rifling with a 1/8 twist rate and M4 feedramps. As with all BCM barrels it is proofed (HPT) and magnetic particle inspected (MPI). To give the shooter the best balance of weight and accuracy this BCM barrel has a mid weight profile and a mid length gas system.

(410 stainless is a harder and more corrosion resistant than the conventional 416 stainless found in most barrels.)

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.

 

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.

 

 

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.

 

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.