BCM MK2 Complete Upper

The BCM MK2 upper receiver represents an evolutionary improvement over the standard mil-spec M4 upper design, offering up to 30% increased rigidity without sacrificing interoperability. The proprietary design addresses barrel deflection under stress, a critical factor affecting consistency and accuracy in demanding applications. This enhanced rigidity also reduces premature wear and failure of bolt lugs caused by receiver flex and misalignment, contributing to extended service life.

The MK2's barrel extension features improved geometry with longer and steeper feed ramps that are machined during the initial manufacturing process. These factory-machined M4 feed ramps are then hard coat anodized, adding significant strength to the aluminum receiver material. The USGI modification extends through both the barrel extension and upper receiver, creating a more reliable feeding path for various ammunition types. All BCM flat top uppers feature USGI-type laser-etched T-marks for consistent accessory mounting reference points.

Like all BCM uppers, the MK2 undergoes rigorous quality control including full assembly, head-spacing verification, and test-firing. The increased rigidity benefits shooters pursuing maximum accuracy potential while maintaining the BCM hallmarks of reliability and durability. The minimal weight penalty of approximately one-third of an ounce makes the MK2 an excellent choice for precision-oriented builds without compromising handling characteristics.