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.
As things turned out, this wasn’t nearly as difficult as I had imagined. Part of that is because of the completely modular approach the entire AR platform embodies, and part was thanks to the specific components that make up my particular build. More on that in a moment.
The barrel going on this beast is a beautiful 16” stainless steel model from Ballistic Advantage. It already comes with M4 feed ramp style barrel extension pre-installed which eliminates the absolute hardest portion of an AR build. Thankfully, in my research, I didn’t come across many (if any at all) barrels for sale that didn’t come with the extension pre-installed. I know personally I would avoid them at all costs. Better to have a competent gunsmith handle that little aspect.
I locked my upper securely in place in the vice, protected by my upper vice block, and gathered all my tools. All that was left was to insert the barrel extension into the upper, then slide the barrel nut over the barrel and tighten it into place. This is where I got my first real snag. Most Ballistic Advantage barrels come with a low profile gas block installed right from the factory. I thought this was fantastic, saving me a step. As a beginner, having a shortcut somewhere that actually has the potential to affect the function of the finished rifle seemed like a nice little bonus. I’ll wait while those of you who have done this before snigger quietly to yourselves. Yep. The barrel nut didn’t fit over the gas block, even a low profile one. Thanks, Ballistic Advantage. As much as I love your barrel, AND the fact that you include the block (and I do, on both counts), having it come installed actually ADDED a step to my build. Not only that, but during the process of removal, I actually managed to scrape the block against the side of the barrel, leaving a 4” mar in the otherwise flawless, bead blasted finish. Oh well, I knew I couldn’t expect everything to go perfectly on my first rifle, with no prior experience.
Take two: Remove gas block. Slide on barrel nut. REINSTALL gas block, taking precautions to make sure the gas port lines up. I used a flashlight shining into the barrel while I looked for light through the gas tube hole. When it was at it’s brightest, I locked it down. Once again, all these roll pins had me wishing for a roll pin starter punch. Not for the last time! Now, where was I? Back to the barrel.
Installing the barrel in most AR-15 builds seems to be an interesting exercise. Your barrel nut is required to be between 35 and 70 lb-ft of torque, but you have to use caution and not just simply crank it all the way to 70 right off the bat. The reason for this is the unique layout of most barrel nuts. These generally have small holes or notches every few degrees in order to allow the gas tube to install through them. In my build however this was mitigated by the use of the Anderson EXT series forearm. One of the things that sets this series apart from others is the narrow barrel nut. Instead of using threading to attach the forearm to the upper, the Anderson EXT series uses a friction clamp method. The barrel nut is very minimal in thickness, but has a very aggressive knurling over its entire surface. Once installed the forearm simply slides over the nut and clamps in place using a few bolts set into its lower edge. This means I don’t have to fiddle with lining up annoying little holes in the barrel nut while still ensuring I’m within the tolerance levels for necessary torque. I just set my torque wrench to a nice 45-50 lb-ft and installed the nut. Anderson claims that you need a special AM-15 Barrel Nut Wrench to use this particular setup, however I found that the basic spanner wrench on my multifunction armorer’s tool did the job quite well. I did make sure to back it back off and re-tighten it a couple times to pre-stretch the threads, otherwise you might find yourself having to adjust the tension again at a later date. I may check it again in the future, but I’m confident that this will remain within spec. Thank you Anderson! This feature actually SAVED me a step!
More troublesome was installing the gas tube into the block. The gas tube is fairly self-explanatory, as one end has a horizontal hole all the way through for the roll pin, and very close to that, a vertical hole through only one side for the gas entry. If you are careful to line up the roll pin hole, you can be confident the gas hole is similarly lined up. At least I didn’t have to worry about the barrel nut. Eventually I ended up actually removing the upper from the vice in order to brace the barrel against a wood block so I could install the tiny pin. That little annoyance seemed to want to go anywhere but through the hole, and almost got lost more than once. Keep your work areas clean, people. You’ll thank yourself later when searching for flyaway pieces.
Installing the Anderson EXT forearm was simple and straightforward. Just slip it on over the nut. Actually locking down the clamps was a little less so. The threaded nut that goes on one side of the clamping slot is press-fit into place in the aluminum forearm. No worries there, right? The only issue is I was the one that needed to press it in place. They seemed to gloss over that in their marketing videos. No problem, I’ll just use the screw to pull it into place as I tighten it. Nope. Obviously the screw will be too short to reach the nut since it’s designed to be flush once tightened. Eventually, I figured out that if I thread the screw into the nut backwards, just enough to hold it, I can use a mallet on the head of the screw to press it into place to the point where I can grab it once threaded from the correct side. Whew. That wasn’t so bad after all. Thread the sling QD receivers into the sides of the forearm (those help with locking it down as well) and installation there is done.
At this point, all that’s left on the business end of the rifle is the muzzle device. As I mentioned previously, I knew that I wouldn’t be able to settle for a standard A2 birdcage style flash hider unless I was presented with no other possible option. Thankfully this wasn’t the case. Just as thankfully, installing the extreme aesthetic of the Ordained Arms Dragon SpitZLead was no more difficult than if it were such a standard device. Simply drop one crush washer over the threaded end, and tighten the muzzle device down until it deforms the washer and lines up with vertical. Much searching of the internet as to which direction the crush washer should face produced mixed results, and I suspect it really honestly doesn’t matter. I did find more that claimed the cupped side should face the barrel and the remainder of the rifle, so I went ahead and followed those.
Time to move down to the receiver for the “Upper Parts Kit” which really only involves a dust cover assembly and forward assist. It’s hardly enough to warrant the nomenclature of “kit” in my book, even when the dust cover comes as separate pieces. This particular dust cover however once again is a Enhanced Ultimate Dust Cover from Strike Industries, and it comes as a single, pre-assembled piece. Not only that, but it’s designed for tool-less installation, requiring at most a bullet tip or pen point to retract the pin and drop it in place. It was, by far, the easiest and most brainless part of the build.
The Forward Assist is the part I had the largest trouble with in this entire construction. The overarching assembly instructions weren’t difficult. Make sure you have the FA facing the correct direction, push in place, and install a roll pin for retention. Once again, it was that pesky roll pin that caused me the trouble. In hindsight, I suspect the process of anodizing the upper might have slightly altered the dimensions of the retention pin hole, similar to the problem I had with the binding pivot pin in the lower, but at the time all I saw was frustration. I eventually compressed the pin’s leading edge enough to allow it to start, but it bound up enough during insertion that it really started to mushroom by the final few hits. In all, the FA still functions exactly as it should, but this is definitely the most prominent mar to my rifle’s aesthetic. At least I know it won’t fall out, right? Right?!
Let’s see. Where does that leave us? We have a fully assembled lower, and a fully assembled upper. Let’s combine them with the remainder of the parts to make a complete rifle. Next time.
Parts in this article:
Upper Receiver – Stripped upper receiver Provided by Anderson Manufacturing
Dust Cover – Ultimate Dust Cover Assembly Provided by Strike Industries
Forward Assist – LDFA Provided by Forward Controls Design
Barrel – Premium Series BA Hanson Provided by Ballistic Advantage
Handguard – EXT Mid-Length, Free Float Kit Provided by Anderson Manufacturing
Muzzle Device – Dragon SpitZLead – Provided by Ordained Arms