Hey guys, ordering my ar 15 parts for my first build ever.  I have been doing a lot of research, but I am confused on what all I need to complete the gun since some things seem to come with pins and bolts and some don't.

So far I have ordered:

Upper Receiver - aero precision AR15M4E1(blem) - ORDERED
Free float hand guard - aero precision AR15 15" Quantum M-LOK handguard - ORDERED $209.99
Bolt Carrier Group - PSA AR-15/5.56 Nickel Boron BCG - ORDERED $99.99
Barrel: LaRue Tactical 5.56 stealth 20" (M4 Feed Ramp) - ORDERED - $342.89
 Larue Gas Block, Gas Tube, Barrel Nut - ORDERED

Lower - aero precision - ORDERED $78.34 + $30 FFL Transfer = 108.34
LPK:
Trigger - ALG Defense Quality Mil-Spec Trigger (QMS) - ORDERED - $51.95
Trigger Guard - Molon Labe Billet Trigger Guard - ORDERED - $23.71


I am waiting on a reply from LUTH-AR to see if their stock will work with my build  ( https://www.luth-ar.com/product/mba-1-black-w-223-buffer-kit/ ). That should take care of the stock, buffer spring, and buffer correct?

I know I will need to order:

charging handle, muzzle device, and sights, but i'm not worried about those yet. Just haven't decided on what I want yet.

I am mostly worried about what else I will need to finish my lower parts kit.  Also, I read something about a receiver extension, receiver end plate, and castle nut.  I don't know what those are, but will I need to order those as well?  

Thanks for any help, and feel free to critique my choices and offer insight on already ordered parts or ones I still need.  As I stated earlier this is my first build and I don't really know what I am doing at all.  Just reading up online and doing my best to pick our some stuff that I think is cool and might make a decent bench rifle and hopefully still good for self defense if I ever need it, and while still staying at a good budget.

Essentially, you need this http://www.opticsplanet.com/cmmg-inc-lower-parts-kit-ar-15-gunbuilder-kit.html in addition to what you've already listed.  That stock/buffer tube combo you are looking at is a rifle length buffer tube/buffer.  You would only need the carbine extension/castle nut/end plate if you were using a carbine extension.

You'll probably want a better trigger to get the most out of that barrel.  LaRue or Geissele 2 stage would be my preference.

You will need a grip too.

Thanks! Yea, I was worried about the trigger.  I probably should have stretched my budget and just got a better one, but I didn't know if it would make that much of a difference.  Unfortunately I already ordered it, so I will just look to upgrade in the future once I get some practice at the range and feel I need one. Also, totally forgot to put the grip in my still deciding section of my post. It's hard to choose one without feeling it for myself. I will go ahead and order that LPK, it looks like it will get the job done and is pretty cheap.

Edit: Just emailed Larue and asked if I could addon their trigger with my barrel order.  :)

Have you researched any tools for assembly?  There are a few that make life easy when assembling the lower, and there are required tools for installing the barrel/ torqueing barrel nut.

I have a little, if you recommend some though I will definitely order them. The easier the better, since it will be my first time.  I am sure I can do it, but any tools that will make it easier would def help.  Also other than the ar 15 wrenches that I see going around a lot, what other tools would be considered necessary? I know I will also need a hammer/pin punches. I may look into buying a ar tool kit that comes with everything.

You'll need something like this to torque your barrel nut, along with a torque wrench.  http://www.weaponwerx.com/product/ar15-combo-wrench

You need to hold the upper or the barrel while the nut is torqued, I prefer the Geissele Reaction Rod for this.  https://geissele.com/reaction-rod.html 

If that is too much money, something like this works as well http://www.ebay.com/itm/NO-M-A-R-AR15-Upper-Lower-Receiver-Vise-Block-223-556-USA-Gunsmith-Bench-Tool-/272810290926?epid=1819868523&hash=item3f84c2aeee:g:vMEAAOSw3ydV5yXl.  If you are going to torque the barrel nut with this set of tools, make sure it is positioned in the vice like the picture shows to prevent stressing/breaking the upper.  This also has the lower block that makes lower assembly easier.  All require a vice.

This is a cheap, made in China, set that works well for installing the bolt catch.  https://www.amazon.com/Wheeler-Engineering-Bolt-Catch-Install/dp/B01B3NU46C/ref=sr_1_1?ie=UTF8&qid=1503189034&sr=8-1&keywords=wheeler+bolt+catch+install.  Bolt catch install is probably the most difficult part of the lower assembly, especially if you don't want to mark up the lower receiver.

You should get some go/no-go headspace gauges unless you plan to let a gunsmith check it for you or you know someone who will loan some to you. Lots of choices out there. You can Google and/or search Youtube for how-to info and why it's a wise decision to ensure proper operation and your safety.

A bench vise, plus this.....
Attached File

OP.... I applaud your decision to get involved with the AR family of firearms. It can be addictive so hang on to your wallet.

That being said, you do know there are many providers of complete kits on the market that provide everything in a nicely bundled package, right?  Lots of options out there for complete rifles for around $400 - $500.  Personally, it made my entry into the build arena both easy and affordable. After the first build I had a much better grasp of all the options and which made sense for my needs.

Lastly, there are tons of resources here in the Arfcom build forum that walk you through all the parts and steps you'll encounter during the build process. Additionally there are some great YouTube videos that show you how to assemble all the parts as well as time saving tips.  I spent hours studying everything I could find before I started building. It made the first build straightforward and alleviated stress and I still have my goto list of resources that I have used for subsequent builds.

Thanks for the feedback! I know there are complete ar builds, but I love to build things. I just built a couple custom computers, I like to work on cars, and I figure I am capable of putting an AR 15 together.  It's just satisfying to me to be able to look at something and say that's mine, and I custom made it. Yea, I have already blown my budget for this one, but you can't put a price on the knowledge I guess. Luckily I really enjoy reading and watching videos about ar 15 rifles.  It's all that's on my mind the past week hahaha.  Hopefully I can keep my wallet safe for a little while after I finish this one!

It's called "BRD" black rifle disease. The main symptom is spare parts growing into completed builds.

Shit 200$ for a Quantum?

I would've gone with the ACT, as in my experience, I've found them to be a lot better for a little more money.

As for the LPK, you can get ones with the receiver extension, end plate, and castle nut. They're what hold the stock on, and where the buffer sits in the rifle.

I like RRA LPKs, ARF seems not too. Their take down pins have a divit to aid in using a bullet to push them out.

Price to Quality wise, I like CMMG LPK.

200$ included the aero precision upper.  The reason I went with quantom is because I didn't want to deal with any hassle of it possibly not fitting perfectly with a different upper.  I picked the aero  upper first, then added on the hanguard after.  It didn't seem too expensive and I think it looks pretty nice. There were just SO many choices haha.  Hopefully I don't regret it! If I do, I will have even more extra parts...and then I will need a bigger gun safe.