DIY AR 15 build-out—in your living room

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Sniper Rifle produced for US special ops teams by Knight’s Armament

by Rob Kay

First, let me confess.


Prior to attending the Shot Show in Vegas in January I wasn’t a big fan of AR 15s or, as they are sardonically referred to, “EBRs” (Evil Black Rifles). Call me old fashioned, but I preferred the look of the traditional hunting rifles with their wooden stocks and avuncular familiarity. I really couldn’t understand all the buzz about the AR 15s.

Was it some latent “GI Joe” complex that had infected the masses?

Was it the zombie craze? (Many of the manufacturers seemed to have jumped on the “zombie” bandwagon by producing guns specifically to dispatch these creatures). Maybe it’s a generation thing, but I have more pressing concerns than worrying about zombie invasions.

Then came the AWB scare. There was a real possibility that Modern Sport Rifles, as the Gun Industry refers to them, might be banned. 

Top of the line AR 15 trigger from Timney. Photo courtesy of Rob Kay.

Naturally when I am told that I can’t have something, I need to have it. Suddenly my interest in AR 15s did an about face. I persuaded an EBR owning friend to let me shoot a few rounds with him at Kokohead. “Not bad,” I intoned, after getting a nice tight little group on the paper.

My interest increased when I realized that you didn’t need to spend $4k on a custom rifle that would shoot (for my purposes) as accurately as a much less expensive AR. After all, the military version of the AR 15 is issued to Navy Seals and the other special ops guys. (Oops there I go with the GI Joe stuff…)

After shooting an AR I commented (well, complained) to the owner about the military style trigger, which was gritty and quite heavy compared to a more refined hunting rifle. His reply was, “What do you expect? This is the way they come.” He assured me that I could easily “drop” a decent trigger in if I so desired.

“What do you mean you can just drop it in?”, I asked. He explained there were a number of aftermarket parts that could be installed with little effort.

This was contrary to my experience. Changing out triggers on a pistol or conventional rifle was definitely a gunsmith’s job. As if reading my mind he said, “You can place a trigger in a lower receiver in ten minutes. He explained that the “build-it-yourself” and customization elements were the main reasons why the AR 15 platform was so popular. Not only could you build one but, you could easily customize it to fit any purpose—self-defense, hunting or simply plinking at the range.

Lower parts kit, aka “LPK” from CMMG.

The aftermarket parts for the AR 15 are endless. They can also be fitted with any number of aftermarket gadgets and “furniture”—custom stocks, scopes, grips, lights, bipod—you name it. “You can build one that can shoot as accurate as a Navy Seal’s sniper rifle.” (Aha, I thought, the insidious GI Joe virus was about to infect me).

Customization was nice but what really surprised me was that anyone could build an AR 15 rifle, much like I built model airplanes as a kid, in your living room. All I needed to assemble one, my friend insisted, was a “stripped” lower receiver and a “lower parts kit” known by gun people as an “LPK”.

It’s that simple but there are rules to follow.

Like any firearm, Federal laws strictly apply. And I mean strictly. Even a “stripped receiver” bereft of all the moving parts is considered a gun and comes with a serial number that must be registered with the HPD. If you purchase a gun it must be shipped through a local Federal Firearms Licensee (aka “FFL”). The FFL then informs the police that it has arrived in the state and the registration process begins.

“Stripped Lower” from New Britain, CT-based Stag Arms.

When I asked Randy Terbush, a gunsmith friend visiting from Colorado if it was really that difficult to build a gun, he assured I was up to the task. Then he corrected himself. “You can build part of the gun—the lower receiver. You’ll need to take extra care when installing the trigger. That’s probably the main issue with the kits.”

If you don’t get it right, the gun can explode.

He suggested, with some help, I could build the whole thing. The caveat was I would definitely need someone akamai in the rifle-building department, as a mentor.  Putting an ‘upper’ together entails some very specific skills and measurements so the help will be necessary.

But one thing at a time.  The first thing we need to do is assemble our parts, our tools and our attention.

Stay tuned…

Questions?  Comments?  Contact us directly at

Rob Kay writes about firearms for Hawaii Reporter and is the author of How to Buy an AK-47.
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  1. To the 2 posters above, as we know, guns jump off racks all the time and mow down innocent people. Seriously? The car in your driveway has more potential to kill somebody all on it's own than a rifle.

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