By Mike Searson
There was a time when an urban kid’s knowledge of firearms was very limited. It was a hazard of being born and raised in New York City, where the only people with firearms were either cops or criminals.
That all changed at the ripe old age of 17 after enlisting in the Marine Corps and cutting my teeth on the M16A2 service rifle.
Marines not only learned to shoot, clean and maintain the M16, but most importantly, we learned how to break the rifle down completely and reassemble it. This skill actually won the author a phone call home for being the fastest private in the platoon to reassemble a rifle the first time out.
Aside from a phone call home (which was an extreme rarity in the wireline era before cell phones, Internet, email, and text) and an ability to break down and reassemble a Milspec rifle while blindfolded, I left the service realizing how easy it is to build an AR from scratch.
Back then you had few resources for building an AR. You either went the route of military surplus parts kits or parts kits from questionable companies that advertised in weekly publications devoted to firearms sales.
The AR was still the redheaded stepchild of the firearms world, but over the years people sought out military guys with time on the M16/AR to build rifles for them on the cheap.
Today, AR parts are easily available from reputable companies such as Brownells that not only stock every part under the sun, but they even have an area on their website dedicated to teaching people to build and work on their own guns.
Aero Precision AC-15 OEM Rifle
When building a rifle, you’ve got a couple choices of where to start. You can buy stripped upper and lower receivers and build the exact rifle you want. There is a bit more skill needed to build a complete rifle from stripped receivers, but a few specialized tools will make the job easier. Alternatively, Brownells offers partially assembled OEM rifles by companies such as Aero Precision that save some time and keep you from losing detent springs or crushing a roll pin or two.
The bolt is properly staked in the carrier, the gas tube perfectly aligned, and those two parts that cause us the most grief (from a time perspective), the bolt catch and ejection port cover, are properly installed from the beginning.
The mid-length gas system is the best fit for a 16-inch rifle. The barrel has M4-type feed ramps and is machined from 4160 chrome-moly steel with a QPQ corrosion-resistant finish. Barrel twist is a 1 in 7-inch twist that lets you run a larger variety of ammunition than just run-of-themill 55 grainers.
The factory trigger breaks at a crisp 5.5 pounds with no creep or slop. We were considering an aftermarket trigger as part of this build, but decided to stick with the “if it ain’t broke, don’t fix it” mentality.
What you have is a perfect starter chassis that allows you to add whatever custom touches you prefer when it comes to stocks, rails, sights, slings, etc. Technically it is shootable in this skeletonized configuration if you want that futuristic, retro Escape From New York look, but let’s build out a proper rifle.
Looking at furniture, here’s the Troy 11-inch Alpha Rail in FDE. Handguards such as this step away from the old-school Picatinny quad rails, which add weight to the rifle and make them susceptible to rail clutter. Troy’s handguard attaches easily and has a built-in safety design to prevent overtightening and causing damage to the rail or receiver.
Three rail segments are included and allow you to put your rail sections where you want them. It’s a good idea to install them before you mount the rail on the rifle.
For a buttstock, check out the Magpul CTR in matching FDE. It installs in seconds over the buffer tube and adds little weight to the rifle.
Perhaps round out the basic build with a set of Magpul MBUS Gen 2 Sights. Guys might have been leery of these when they first came to market a decade ago (when many ARs still sported carry handles ...), but most have come to find them a good value for irons if your rifle has none.
Everything else from this point on are accessories that might not be essential, but add considerable utility to the rifle.
One of the virtues of the AR platform is that you can accessorize it until your heart’s content. Over the years, ARs have been adorned with flashlights, green lasers, IR lasers, night vision scopes, long-distance scopes, reflex sights, silencers, and anything else you can think of.
Yet, you really only need two accessories to complete a basic rifle: a light and a sling. Those two accessories, however, need a few adapters of their own.
In the old days with wood-stocked rifles, you simply installed sling swivel studs where you needed them and attached your sling. For decades ARs followed the military model: two sling swivels are perfect for mounting a parade sling, but not so much for running a gun in the real world.
You can mount a pair of flush-fitting Midwest Industries QD Swivels easily on the Troy rail and CTR stock, and this setup lets you run a Viking Tactics V-Tac Sling with IWC QD sling attachments installed on the sling itself.
The V-Tac sling is more than just a carrying strap. It’s completely adjustable and can be used as a stability-enhancing shooting aid — something that many manufacturers seem to forget these days.
Up next is the flashlight. The Streamlight Pro-Tac HL Light is an inexpensive handheld light with three settings. The advantage of a light like this over a dedicated weapon light is that you can remove it and use it as a handheld, should you need to do so. Maybe you need to sling the rifle because you’re carrying something or someone, or you’re conducting a search and don’t want to point your rifle in an unsafe direction to use your light. It gives you those kinds of options.
While it’s less expensive than a dedicated weapon light, you will need to buy a couple of parts to attach it to your rifle. The Viking Tactics Flashlight Mount bolts the Pro-Tac HL to our forend. Rather than go with a tape switch and run a cord, look for something that would make Marine Corps drill instructors and primary marksmanship Instructors have a full-on stroke: a Magpul vertical fore grip.
They have their place on full-auto guns or short-barreled shotguns to keep your hand from sliding forward of the muzzle, but on a rifle they can cause you to “muscle the weapon.” Guys got over that when they found better ways of attaching light to rifle than with hose clamps and electrical tape. It allows you to run the light better by putting your non-shooting hand in close proximity to the switch, letting you activate and deactivate the light with a single finger. Because you’re not using a quad rail handguard, you have the option of grasping the handguard in a traditional grip and not using the VFG if you so desire. And, options are good.
OK, There's a third accessory: Optics
A few years back, many people would’ve scoffed at optics on a basic AR. Common advice would have been to put the money into an improved trigger, but as age catches up with us all, easily seen red dot sights have become popular and the Vortex SPARC II offers a balance between value and performance.
It’s a rugged and reliable sight that comes with three different risers; the tallest allows a co-witness arrangement with the Magpul BUIS. Its 2 MOA-sized dot has 10 intensity levels and is night vision compatible. They may not be seeking any military contracts, but decent shooters will be able to shoot clover leaves at 40 and 50 yards all afternoon with it.
The low price point may lead some shooters to dismiss it as a budget optic or as an Air Soft Plus kind of deal, but it’s durable and accurate enough for anyone in the market for an inexpensive red dot. It’s a sight that any AR shooter can afford.
We took this very build out to the range with a few hundred rounds of PMC Bronze 5.56 (also available at Brownells) and some standard GI 30-round magazines. The SPARC II caught our eyes immediately and it co-witnessed perfectly with our front sight. At 50 yards we shot two quarter-sized groups. Then we turned our attention to whacking tennis balls and steel silhouettes at varying distances.
At this point we really regretted not going with a magnified optic, because the potential for accuracy with the Aero OEM rifle is definitely there. A 4x scope would have helped us see the target better and reduced our group size significantly.
Aero Precision has the two key elements of the rifle down to a science: the barrel and trigger, or as we refer to them: the heart and soul of the gun. This rifle build may seem very basic to many readers, but if you’re an adherent of the K.I.S.S. principle it will meet 99 percent of most shooter’s needs for a defensive, three-gun, or even a patrol carbine.