construction an Ar-15 - Lower Receiver

Lately, I had taken up a growing interest in firearms and decided to buy an Ar-15. I'm kind of a cheap-o, so I went with the Diy route. Basically, the Ar-15 is divided up into two parts - the lower and upper receivers.

The lower receiver is made up of 3 main items:

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1) Stripped lower receiver - basically a hunk of metal with holes and openings, no enchanting parts
2) Lower Parts Kit (Lpk) - contains all the parts you'll need to complete the lower and assemble the trigger, trigger guard, hammer, magazine catch, and bolt catch
3) Stock - these all vary in styles, from fixed A2 style to 6 position collapsible stocks

I found my Dpms stripped lower receiver at a local gunshow. I would strongly advise that you check out a gun show before ordering online/locally. Usually, there are some decent deals colse to and you won't have to pay the Ffl exchange fee as you would if you bought it online. By the way, the only part that is regulated by the government is the stripped lower receiver. This means that background checks and laws apply to lower receivers the same way they apply to fully completed rifles, pistols, etc. On the plus side, once you have the stripped lower receiver, you can order/buy all the other parts without any hassle and have them shipped directly to your door.

For the lower parts kit and stock, I went with Dpms. This was because I got a good deal at SportsmansGuide.com on the parts and I was trying to keep things as cheap as possible. I ended up paying shipped for the Lpk and shipped on the 6 position stock.

Putting the lower receiver together is not very difficult, but it can get frustrating at times. I used this guide from the Ar15.com forums from start to finish. I advise that you print out the guide first, lay your parts out as shown in the diagram, then begin assembling the lower. No extra tools are needed, however, you will want to have some punches to punch in the roll pins. You can just get the appropriate pin punches, no need for specialized roll pin punches if you want to save some cash.

I started putting together the lower without any punches, but when it came time to punch down the trigger guard roll pin, I was wishing I had one. Trying to improvise, I used my Swiss Army multifunction tool to hammer in the pin. After at least 15 minutes, I had ultimately gotten the pin in, but left the trigger guard all scratched up from my barbaric hammering. Not only that, but when you have to drive the bolt catch roll pin in, you will wish you had a punch. There is not enough clearance in the middle of the pin and the rifle to McGuyver something to drive the pin; you must use a punch!

Other than that, the rest of the process went fine. Only thing is, I'll need a Car wrench to tighten down the stock, but it should be too big of an issue.

construction an Ar-15 - Lower Receiver

construction an Ar-15 - Upper Receiver

When finding for an upper receiver for your Ar-15, it is leading to do your research and note the dissimilar features offered by each company. Although the upper receiver is for an Ar-15, each company has their own highlight set. Straight through my research, I found the Cmmg 14.5" upper receiver to fit my needs the best.

The main conjecture I chose the Cmmg upper was because of its features and price. The faultless upper ran 0, not a bad deal and right at the price point of other close mid-level competitors such as Bushmaster, Stag, Dpms, etc. What sets Cmmg apart is its mid-level price with high-end features.

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Some of the more noted features include: Chrome lined barrel, 4150 steel 1:7 twist M4 Feedramps 5.56 Chamber.

The chrome lined barrel helps in preventing rust and prolonging the life of your barrel, with the disadvantage of reducing accuracy very subtly vs a stainless steel barrel. On the flip side, chrome lined barrels are very easy to clean and don't need to be cleaned as often. 4150 steel is higher grade, mil spec steel used in combat rifles given to our forces in Iraq. Some mid-level brands use 4140 steel, a slightly lower quality.

The 1:7 twist allows the rifle to shoot heavier rounds. The primary M16 had a 1:12 twist which would only stabilize rounds up to about 55gr. A 1:9 twist barrel (like most mid-level fellowships offer) could allow you to shoot heavier 75 and 77gr rounds, but the stability is iffy from brand to brand. However, the 1:7 twist will stabilize the heavier rounds just fine which makes it perfect for anti-personnel/home defense rounds.

M4 feedramps are debatable as seen in the forum post I linked to. I'm right on target with the author of the post, "if they will preclude one arresting in 1k rounds, and cost Me nothing extra, I want them." However, if you end up finding a good deal on an upper without M4 feedramps, don't let it be a deal breaker. Many people have reported no problems without M4 feedramps, but if you're getting a new rifle, why not get the latest tech?

A 5.56 chamber will let the Ar-15 shoot .223 as well as hotter 5.56 rounds. On the contrary, you should not be shooting 5.56 out of a .223 rifle. This is because 5.56 rounds are loaded to higher pressures than acceptable .223. If you were to shoot 5.56 out of a .223 rifle, you could potentially damage the weapon. The benefit of 5.56 vs .223? For the most part, accuracy is slightly best with the 5.56 and the velocity is slightly higher. Bottom line: I want to be able to shoot hotter loads should I need the stopping power in case of emergencies like a home invasion, Wwiii, 2012, zombies, etc best to be safe than sorry and best to have it and not need it rather than to need it and not have it.

The linked forum thread at Officer.com should help you a whole lot in choosing which upper to get. I'd recommend you to look Straight through the dissimilar brands, weigh the pro's and con's, price and performance, then make your decision. However, if you've got tons of cash and want the best, just get a Colt.

construction an Ar-15 - Upper Receiver