Building an AR15 and a few other questions

[Hoop]

I'm kind of a newbie at this so I am looking for some guidance. I'm interested in getting an AR15. Near as I can tell, there are four ways to get one.

1. Buy a complete assembled rifle.
2. Buy a completed upper half and a completed lower half. Easy assembly.
3. Buy a complete parts kit and a stripped lower receiver. Trigger will need to be assembled, will need to be headspaced, etc.
4. Buy the whole thing as parts and have it assembled.

More or less correct? I will also make the assumption that as you go from 1 to 4 things will generally get cheaper but will require more assembly.

When going routes 2-4, the lower receiver (whether strippped or complete) is the 'gun' and is what requires FFL handling. The rest can be ordered off the internet/where ever. Correct?

That's all for now. Thanks!

 

[Beren]

You've got it down right, I think. Assembling the lower is simple. Putting the barrel on is something I haven't tackled yet, I've been buying my uppers complete.

 

[Bartholomew Roberts]

If you buy a completed upper, it should be headspaced at the factory. For that matter, the only way you would encounter problems with headspacing on the AR15 is if you were using very worn, old parts or if whoever installed the barrel extension was grossly negligent.

I like to check headspace anyway because I have the gauges and I'm a little skeptical about trusting my safety to some of these outfits. Having said that, I've never had one fail a headspace check.

Putting on a barrel is a little more involved than assembling a lower and you'll benefit from some specialized tools, especially a vise, delrin upper receiver block and an armorer's wrench (not the cheap GI wrench). A punch set is nice as well.

There are several manufacturers who can sell a complete AR at a price level that is competitive with a parts AR. The main advantage you get with building your own is a slightly lower price (due to lower excise tax) and the ability to use the specific parts you want rather than whatever parts a particular manufacturer offers.

 

[Rexrider]

I am a big fan of # 2 when buying a first AR. You can still save money and not have any concerns about having a safe and functional AR. Push two pins and you are ready to go.

Do a lower or full build for your next AR (oh..and you will want another AR).

Just an opinion, your milage may vary.

 

[Cortland]

I just bought my first AR-15 using method #4. I bought a stripped lower receiver locally, and bought everything else from Brownells -- down to individual springs and roll pins.

It's easy to do, but having some experience disassembling/reassembling guns is probably necessary. Start to finish it's something you can do in an afternoon -- and it's fun! As Bart said, the only specialized tools you really need are a receiver block, armorers wrench, roll pin punches, and snap ring pliers (all together <$100).

You can buy parts sets to assemble your lower/upper with, but I bought everything separately because I wanted things like a NM trigger, NM sights, special furniture, etc.

If you plan on building any part of your rifle, you really should have a C&R FFL. The discounts from Brownells and MidwayUSA will save you lots and lots of money.

 

[Don't Tread On Me]

You're partially correct.

It's more like this

1] Complete rifle
2] Complete upper/lower then assemble.
3] Complete Kit less stripped lower receiver.
4] Build from sub assemblies
5] Build from parts


#5 is impossible unless you are a gunsmith or a manufacturer of AR's. The reason is simple, it simply is not cost effective to buy every single part. Also, the barrel itself is an assembly, and that is where headspacing is done. This is done all together with the indexing pin/barrel extension installation, gas hole drilling etc....needs gunsmithing tools, or other advanced set ups.


#4 is what most people refer to as "parts". You build using a barrel, hanguards, upper receiver, Bolt carrier etc....all the parts are seperate. In other words, the upper doesn't come assembled. Note that the barrel is a "part" but it is really an assembly. It will come from wherever you buy it with a front sight base, barrel nut, and barrel extension already installed. It will be pre-headspaced at the factory. All the rest of the parts in this method of building are somewhat complete parts...you can buy a stripped upper receiver, but you won't save that much vs. just buying a complete upper receiver that already has the ejection port door, rear sight (if A1/A2), and forward assist already installed.

You will need the following tools.

a] action block (assuming you have a bench vice)
b] barrel wrench
c] torque wrench
d] 4 specific sized pin punches
e] moly grease
f] a castle nut wrench (if you get an M4 or Car stock)
g] a non-marring hammer


Optional tools would be: Detent pin tool (this is overrated, installing detent pins are easy). Handguard removal tool. This is GOOD to have. It's a pain to get the delta ring compressed to remove the handguards.

#3 is a "kit gun". The kit comes with everything you need except a stripped lower receiver. The lower is technically the gun by law, so this is bought seperately. The upper is already assembled, all you build is the lower by putting in all the fire control group parts in, attaching the stock and grip etc...You'll need 3 pin punches. 1 for the trigger guard, one for the bolt catch roll pin, and 1 for the trigger/hammer pin. Possibly a castle nut wrench for collapsible stocks.

#2 I wouldn't do this option unless I didn't want to do ANY kind of assembly myself, or I want factory made rifle upper/lower to make a configuration that I couldn't find as a single rifle.

#1 makes life easier, but you won't know your AR as well. Out of all of these, this option at least gets you a warranty.

 

[NMshooter]

If this is your first AR, buy factory.

You can afford to make a few mistakes on the second...

Removing the front sight base is a major pain in the butt. Everything else is pretty easy compared to that, including installing the barrel in the upper receiver.

Get the special tools before doing a full up build or rebarreling an upper, otherwise you will regret it.

The barrel should already come headspaced, headspacing is done when the barrel extension is installed. Purchase bolt carriers with the key already installed and hydraulically staked at the factory, and look at the carrier to make sure the key is properly staked. This will save you numerous problems in the future.

Have fun!