As I’ve mentioned, final assembly is truly the easiest construction you’ll do with your rifle. It hardly qualifies as construction, in fact. I’ll admit, I watched a video or two to ensure I was doing it right, but it’s so simple I could have figured it out without the assistance.
Finally, I’ve managed to free up the necessary time to assemble the upper. I’ll be honest, I was a little nervous about this one, since in all my research, installing the barrel always seemed like the most particular and complex component. With all the specific torque figures, and alignment concerns, plus the fact that this is where the bang happens, I was very concerned about getting it right.
With a fully assembled and functional lower, the actual firearm, as far as the US government is concerned, is complete. Almost all of the determinations of caliber, power, size, and aesthetic are a function of the upper. For this portion of the build I was once again turning to a number of different manufacturers for a variety of different parts. The beauty of the AR platform lies truly in its modularity. Any parts that are labelled as Mil-Spec should be dimensionally compatible. True Military Specifications are a post for another time, however the term has evolved in context to mean a set of dimensions and tolerances that allow for interchangeability of parts between any number of manufacturers.