BCM 14.5" MID LENGTH UPPER RECEIVER GROUP WITH RAIDER M13 HANDGUARD

These Barreled Upper Receiver Groups are designed for shooting professionals and responsible civilians with the Mil-Spec features for the demands of their duty. They are fully assembled, headspaced, and test fired.

BCM's RAIDER (Ruggedized Aiming Infrared Device Enabler Rail) handgauard
The RAIDER is built using a double wall extrusion creating one of the MOST RIGID FREE-FLOAT PLATFORMS in its weight class. Its unique architecture balances weight, rigidity, and capability translating to a more consistent zero retention with handguard mounted electro-optics and lasers. MIL-STD-1913 remains the most durable interface for mission essential equipment. Accordingly, the BCM RAIDER offers Pic rail where these enhancements are most likely to be positioned with six channels of Pic rail interface at 3, 6, and 9 o’clock, as well as an uninterrupted 1913 rail along the top of the hand guard.The RAIDER rail also features either MLOK interfaces at 3, 6, and 9 o’clock for the placement of additional enabling accessories. Finally, a series of ports have been positioned to enable pass throughs for securing vital equipment with zip ties or MIL-SPEC cording.

M4 Feed Ramp Barrel Extension and Upper 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 upper receivers 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, private security personal, and personal defense for its' superior ballistics.

Mil-Spec Barrel Steel (Certified Mil-B-11595E)

BCM barrel steel is Mil-Spec per MIL-B-11595E, and is independently certified. 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. This 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.
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.

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 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 or high quality personal defense ammounition.

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.