The Mk1 AR-15 Assembled Upper Receiver comes with the port door and forward assist already installed. Forged from 7075-T6 aluminum, this assembled upper is precision machined to mil- spec M16/M4 specifications and features M4 feedramps.
Terra Brown Anodized Color Note: While we strive for consistency in the color of these components, there are some inherent differences in final color outcome that are out of our control due to the anodizing process which depend on many process parameters such as material alloy (6061 (Rails, optic mounts) 7075 (upper/lower receivers, charging handles, receiver extensions), material heat/lot, material process (extrusion, forging, impact extrusion, etc), material condition raw or machined/cut, anodizing water process temperature, acid etch time, rinse speed and time, dye concentration, anodize time, current intensity, blasting media condition, blasting angle variation, etc. This is well known at this point among consumers in the industry with "fifty shades of FDE" colloquialisms describing the variations in color possible in anodizing of colors lighter than black. The product you receive may be a somewhat different color than what is pictured due to these aforementioned variables in the electro-chemical process. Additionally, small cosmetic imperfections usually hidden by the black anodizing process are more easily seen due to the lighter pigment of the Terra Brown dye. Because these issues are inherent to the process, slight cosmetic imperfections may not be pulled from inventory and marked as a blem. This is a risk of purchasing a non-black product and should be expected to a degree. We will not sacrifice the functional performance of our products, and any issue that affects performance will not be sold. Anodizing fortunately doesn't have the level of increased cost premium associated with the intensive labor involved in painting rifles (something we simply don't have the available labor pool locally to support, nor do we believe the customers want to pay the premium for), so color being possible in that atmosphere at no additional cost is a major process benefit of anodizing. If the above mentioned conditions are unacceptable to you, we encourage you to purchase black anodized parts.
