I must confess, the AR-15 platform confuses the heck out of me

[W.E.G.]

I'm still waiting for the movie scene after an indoor gunfight, where everyone is deaf and going "Huh? What did you say?"

Remember to include lots of blinking, eye-rubbing, hand-waving in between the face and the charging-handle, and shallow, annoyed coughing to add authenticity to your screenplay. Oh, and complaining.

Kind of a Revenge-of-the-Nerds meets Blackhawk Down.

 

[Powderman]

A couple of tips....

1. Make sure that you use the correct buffer/spring combo for your upper. It has to do with gas port pressure.

For the 20" and longer only, the stock buffer and spring will do nicely.

If you're going to go with the 16", you need a carbine buffer (heavier and shorter) and the carbine spring to go with it.

Shorter barrels use even heavier buffers to make the weapon function correctly.

2. Make DARNED sure that your bolt carrier key is staked properly. One of the major problems with functioning trouble is a loss of gas from the carrier key.

A properly staked key should have four distinct, heavy swage marks, pressing metal toward the bolts, two per bolt. You should actually see metal displaced toward each bolt. For an example of a properly staked carrier key, see a Colt bolt carrier group.

3. If you have ever felt the need for speed--as in rapid firing, bump firing, just mow down those targets kind of thing, you NEED a chrome lined barrel. The US Gov't went to chrome lining because it stands up to the heat of lots of rounds going down range, really fast.

Some will tell you that "hey, the chrome's in the steel, you don't need that...." WRONG!! You want chrome lining. If you do get a regular steel or match unlined barrel on the rifle, follow the same shooting guidelines as for a precision bolt gun: NEVER let the barrel get hot! It is entirely possible to ruin the accuracy potential of an unlined AR barrel by rapid firing as few as TWO 30 round magazines.

4. As has been mentioned before, buy a complete upper receiver group. Assembling a barrel to a stripped upper is indeed possible--but you're going to spend a LOT of money on tools that you will possibly use only once.

5. Finally, don't be penny wise and pound foolish. Spend your money on quality ONCE--that way, you don't have to replace substandard parts over and over again.

 

[dust_101]

1. I need to finish out the lower receiver, where and what should I buy? Is a drop in trigger housing good or just easy? I like a good trigger but don't need anything too fancy or light. Something close to my Kimber would be ideal.

Best bet would be to pick up a DPMS lower parts kit (LPK) which you can get new in package on Gunbroker for $50 (the guy I bought mine from swapped in a Magpul winter trigger guard for little cost)

2. Should I get a complete upper or buy the parts separately? I want a flat top with carrying handle (I'll add optics at a later date). I'd like a good barrel but don't need a super duper tack driver. What is a good barrel when it comes to quality vs. accuracy. I think I want chrome lined.

Get the complete upper, I did mine myself with some help from on-line sources, and it wasn't THAT hard but unless you get a real deal on each part you're better off with a complete upper. As for who, I'd highly recommend Stag, their upper and lower fit is nice and tight, if you add on another maker you may have a slightly loose fit between the upper and lower and need to buy these little spacers. If you want to see where to buy one, you can browse the dealers on AR15.com and they are usually reputable folks to work with. If you think you want Chrome Lined, get it. If you are only going to the range with your rifle you may not need it.

3. I'd like the foregrip to give me the option to add a light in the future.

Way to many options, and they are pretty easy to swap if you don't like the stock ones that come on the upper you buy.

4. I think I'll go with a collapsable stock. Are they all about the same or do I need to beware of certain brands?

Again, pretty good options out there, nothing to really avoid. Keep in mind any local laws... ie in NY I can only use a fixed A2 style or a pinned A4 (or a stubby A2 which is pretty sweet).

5. I believe I've settled on a 16" barrel to give me more indoor maneuverability. What am I giving up accuracy wise if I get a 16 incher vs. a 20 incher?

Not much, but that depends on what you will use the rifle for. I planned mine out for 3-gun style shooting so I went with a 16" lightweight Colt barrel in 5.56 NATO. If you want to go long range varmint you would want a heavy long barrel with a lightweight trigger to maximize accuracy.

Good luck with your build and welcome to the world of BRD (Black Rifle Disease).

Here's what my build ended up like (for the time being.)

 

[jmtgsx]

Great post, Dust.
I'm probably looking at a RRA complete upper in .223Wylde that will chamber both .223 & 5.56 NATO. After reading several threads on here and at arf.com, I really dont see this advantage discussed much. Is it really an advantage? What is typical price difference and is one more inherently accurate than the other?