Thread by @Tectomancer, Ok everyone, A while back I asked my mutuals if there was [...]

Ok everyone, A while back I asked my mutuals if there was an interest in an AR building how-to, and there was, so I am going to start working on that. I am still missing a couple of parts, but I'm going to get started.
#ArmTheLeft #LeftARBuild

Tools:
The stuff at the top is necessary, the stuff at the bottom is desirable and will make your work easier and higher quality. The next tweet will list necessary tools, the one that follows that will list desireable tools. (2)

Necessary tools:
Top center- 1/2" torque wrench
2nd row, left to right- Hex (Allen) & star drives, reaction rod, and punch set.
Not shown- Castle nut wrench (couldn't find mine-lol), small brass headed hammer (currently loaned to a friend)
(3)

Desirable tools:
Left to right- Pivot pin and detent install tools above a container of lapping compound, receiver lapping tool, small torque driver, jewelers vice blocks, aluminum AR vise block.
(4)

I will explain what each of these tools is for as we go.
Sources to purchase tools:
http://brownells.com (these guys make the best reaction rod-I'll explain why when we use it-they have other tools as well)
http://midwayusa.com
http://gandgrifleworks.com (lapping tools)
(5)

MidwayUSA - Shop Shooting, Hunting, & Outdoor Products

MidwayUSA sells Just About Everything® for Shooting, Hunting and the Outdoors; our Nitro ExpressTM provides Super-Fast, Low-Cost Shipping.

http://brownells.com

Ok, when you build a custom AR, you want to have some kind of philosophy for construction, and this will drive parts selection. For instance- you want it to be lightweight, or you want it to be accurate at long range, or you want it to be compact for home defense.
(6)

In my case, for this build, I am constructing the entire rifle around a trigger. I have a binary trigger from Franklin Armory (available at the Brownells link).
(7)

A binary trigger is a select fire trigger that allows you to choose between semi-auto fire (gun fires each time you pull the trigger) & binary fire (gun fires each time you pull the trigger & fires again when the trigger is *released*).
(8)

This type of trigger allows you to attain a cyclic rate of fire that is comparable to a full-auto rifle (on a full auto rifle, the gun will continue to fire as long as you continue to depress & hold the trigger).
This is completely legal in most states (check your state law)
(9)

So due to the specific trigger that I selected, I'm building this rifle to operate under and survive very high rates of fire, with the heat, dirt, & fouling that will accompany that type of shooting- selecting parts accordingly. I'll explain as we go.
(10)

Now, if you do not want to get that far into the weeds, there are full parts kits you can buy from some sellers. These parts kits will include everything you need *except* the lower receiver and a sighting system.
(11)

When buying parts, please note that the *only* part that is regulated is the lower receiver (see pic). This is the portion of the firearm that has a serial number & it must be shipped to someone with a Federal Firearms License in your state & transferred to you by them.
(12)

Most online dealers have a database of dealers that they work with (Brownells probably has the biggest one). You order the lower and pay for it online, provide your name, address, phone #, along with your dealers address/contact info & they'll ship it to them.
(13)

Dealers charge a fee for this service, usually $15-$25 in my experience. If you do not know your FFL, give them a call and tell them you are planning on buying a lower receiver from the seller you've chosen and ask them if they will accept shipment & do transfer (they will).
(14)

I've always felt it was good to give the FFL a courtesy call, unless you have an established relationship. The online seller will provide any instructions (They will want the FFL to email or fax them a copy of the FFL license if they do not already have it on file)
(15)

Sources for lowers (as well as other parts):
http://aeroprecisionusa.com (my personal fave)
http://palmettostatearmory.com
http://brownells.com http://rainierarms.com

Rainier Arms - Pursue Your Passion

Rainier Arms specializes in high-end AR15 parts, AR15 accessories, AR15 grips, AR15 stocks, AR15 uppers, AR15 lowers, AR15 barrels and much more...

http://aeroprecisionusa.com

Sources for full parts kits:
http://palmettostatearmory.com
http://davidsondefense.com

A note about receiver materials & construction methods:
7075 series aluminum is better than 6061 series aluminum. Almost all are made of 7075, but if you see 6061, avoid it as it is weaker.
(18)

On forged vs billet:
Many of the "high end" receivers are machined from billet. A solid block of aluminum is machined down to the final shape of the receiver. In forging- blank is placed into a machine and the receiver is hammered into shape.
(19)

Many people like billet receivers because they look much more unique with different features than military style AR's (if you search for some you will see this), however a billet receiver is not as strong as a forged receiver.
(20)

The hammering action of forging causes the molecules of the alloy to become denser and align themselves, & this is what increases strength. A forging machine & it's associated tooling are very expensive, so forged receivers have a lot less aesthetic variation-they look plain
(21)

Some manufactures combine these two methods in a hybrid process. Aero Precision does this- there are others as well.
(22)

Parts. See pic below, I will label each part in following tweets. Unfortunately, I already had my lower receiver assembled prior to deciding to do this tweet, but hopefully I can do another build and detail that.
(23)

From top to bottom/left to right, the parts are as follows:
Recoil spring, buffer, charging handle, upper receiver (most come assembled as shown), bolt carrier group, lower receiver (assembled), free-float hand guard, barrel, muzzle device washers, and muzzle device (brake)
(24)

Lower receiver parts (you can buy these in a complete kit, with or without the trigger):
Buffer tube, castle nut, end plate, buffer retainer & spring, take-down pin/spring & detent, safety selector/detent & spring, bolt release/pin & spring, magazine catch/button & spring,
(25)

(cont.) pivot pin/detent & spring, grip, collapsible stock, trigger pack, & anti-walk trigger pins (highly rec you get these-trigger pins are hardened steel that vibrate & can rotate and are set in aluminum-they prevent the pins from wearing the holes larger in the receiver)
(26)

Why does my upper receiver look different from others you may have seen? Please see the comparison in the photo below. Some makers use a proprietary stiffening lug on the front of the uppers, such as Aero Precision (forged) & Seekins Precision (billet).
(27)

A conventional or mil-spec style receiver is on the right. Notice how much more material there is around the barrel connection area on the receiver on the left (an Aero receiver in this case). This creates a much stiffer receiver/barrel connection that is less prone to flex.
(28)

Also- on the Aero receiver, the barrel fits inside the lug, the barrel nut then has male threads that thread into female threads in the lug, & the handguard then attaches to the outside of the lug rather than directly onto the barrel nut as on a conventional upper.
(29)

This means that forces exerted on the handguard are not not as directly transferred to the barrel.
The drawback to this is that you can only install comparatively fat handguards made by Aero Precision.
(30)

Conventional uppers are quite serviceable and have more parts interchangeability, but I like this system as I believe that it provides an increase in accuracy.
(31)

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