Friday, September 7, 2012

So... ARs...

So when you buy a stripped lower, to get the rest of the gun you need to buy a "Stock Kit" and a "Trigger Kit" and an "Upper."  Is that right?

I need to carve out some time and watch the Brownells video on putting an AR together from parts.

But the Stock and Trigger kits...  They look common in the catalog houses, and I think the idea if to give you the whole spiel of that part of the rifle.  Is there some group of parts you won't have if you get those kits?

I'm budgetting and slowly accumulating.

And then... will I need specialized tools?  I know there is a do-hicky for getting the handguard on and off, but you won't need that right away if you get a complete upper.  There is also a wrench like multitool thingamabob that covers a lot needed tools.

The sort of upper I have my eye on is this.  A carbine length item with brass deflector and a flat top.  Will need EOTech type optics and BUIS, naturally.  I'd get a light mount and a foregrip too, but nothing else.  The stuff I've added is heavy enough.


bluesun said...

You can use a set of big channel pliers as the handguard doohickey, at least.

Marty said...

I have an entire stock and foregrip assembly you can have if you want. At least until you acquire the exact one you desire.

oddball said...

Probably not recommended, but the only special tool I bought for building my lower was the AR wrench. instead of using the vice block, I just wrapped the lower in a towel and was careful not to over crank the vice.

Like I said, not recommended, but it works.

ZerCool said...

You will need a stock kit, defined as:
- buttstock
- buffer tube (receiver extension)
- buffer spring
- buffer

You will need a lower parts kit, which is the trigger and assorted other pieces to make the receiver functional. Generally they include the basic A2 plastic grip as well.

You will need a "complete upper" WITH "bolt/carrier group" (BCG).

The only tools you need to put together a lower are a small hammer, a set of vise grips or channellocks, and a set of needlenose pliers. I'd HIGHLY recommend adding in a set of AR pin punches.

There's a "build your own lower" post on that I've referenced over and over.

Geodkyt said...

Ditto on the assembled upper, unless you're planning on doing enough ARs that the torque wrench and receiver block are cost effective purchases. Installing a barrel with the barrel extension already properly pinned on into an upper is fairly easy, with the vice block and torque wrench.

If your upper has M4 feed cuts, your barrel extension needs them. If your barrel extension has them and your upper doesn't, it's not so much an issue. (I like them, but they aren't critical unless you're running an honest-to-God SBR M4, especially in BURST or AUTO.)

On the other hand, you can get your bolt carrier group seperately -- any new, in-spec bolt will be properly headspaced to any new, in-spec barrel. Once the parts have worn into one another, you don't want to change out the bolt unless you absolutely have to. DO NOT change the barrel extension unless you have experience doing it AND you have teh proper setup.

You want a chrome lined bolt carrier with the gas key staked like Thor was beating on it. You do not need a chrome all-over carrier, although they look pretty and are easier to clean cosmetically. (The chrome lining inside the carrier is what really counts for reliability. Some of the newer alloys like NP3 are good chrome substitutes.)

DO NOT buy a barrel that does not already have the barrel extension professionally headspaced and pinned. Until the barrel is headspaced, it's just a very expensive tomato stake; with the very expensive professional setup, it's a snap -- without the production-line style setup, it is a very finicky process that is easy to screw up a barrel beyond repair doing, so it is not something you want to do yourself at home.

Buy the best barrel you can, and any bolt that is milspec or better. I've heard good things about the FailZero bolt groups. The barrel is the soul of accuracy in an AR, and the bolt and the barrel group should be married "until death do they part" for headspacing and wear reasons.

If you want a good trigger, I cannot over-recommend the Gissele SSA. It is expensive, but my God is it nice. . . without being a delicate match queen. Luckily, triggers can be swapped out later down the road, pretty much at will.

That Guy said...

I'm in the same boat as you. I just bought 2 stripped lowers, and I am waiting on the first parts kit to arrive.

Ritchie said...

The buffer tube nut wrench is very handy to have. Be aware that commercial and milspec buffer tubes are slightly different diameter, and will require matching buttstocks. I have a 16" ar with carbine length gas system like your example. I suggest a mid-length gas system instead, since the short gas tube gives a fairly abrupt bolt opening and extraction. This strains the parts a little more, and over time could lead to wear and malfunction, as well as possible damage to you brass. Study on the spring system for the extractor-standard spring and black buffer have been working fine for my semis. "The Gun Digest Book of the AR-15" may be of interest.

Ritchie said...

Also, if you end up with extra parts, you know what that means, right? Lowers are cheap.

Angus McThag said...

If you are going to build a second lower get the pivot pin detent tool. Saves a LOT of aggravation. Oh, and aim the spring DOWN into something that won't let it bounce, like a pillow when you're putting the pivot in past the detent. When you lose one (and you will if you build enough lowers) you'll understand.

Channel-Locks get all the roll-pins in place, but you need punches to get them all the way centered. Seeing one side flush with the edge of the hole will eat at you. You will definitely need punches to REMOVE any roll pins later, so you may as well get them now.

A stock wrench makes putting a carbine stock on much easier, but a good quality strap wrench will suffice. Don't forget to stake and avoid loctite like the plague!

The two fixtures that let you clamp your work in a vice are labor savers. The upper block is essential if you're going to do your own barrel installation. The one for the lower is just a third hand for getting the stock on tight.

I'll second the thought on the mid-length gas system if you're going with a 16" barrel. It's simply better than the carbine length. Carbine is putting higher pressure in the tube and will do it longer than it needs to because a non-NFA gun has an additional 1.5" of dwell (or more). The carbine system is a bit of a bastardization. It was created with a 10" barrel in mind, but it was found that it was not reliable until you extended the barrel out to at least 14", then they added another 1/2" so a bayonet could be used.

BC said...

If you can get an overly large clear plastic bag to put the lower in as well as your hands and a tool to install the damn front take-down pin detent it might save you having to buy spares when they vanish into nowhere at a high rate of speed.

A set of roll pin punches, roll of masking tape and a small hammer get the rest of the lower together pretty easily. You probably won't need the handguard tool if you have decent grip strength, but if you are going to have your handguards off and back on often it might be handy.

No locktite on anything, torque & stake per specs, and buy good quality parts the first time around so you don't have to do it twice. Also, I'm a fan of light-weight midlength uppers as they handle and shoot nicely.

Good Luck!

Anonymous said...

"Gunsmithing the AR" by Patrick Sweeney on amazon and well worth it. Other than that youtube.
www.mapartsinc. Just buy the whole kit as a unit and save much time grief and $$$

Anonymous said...

Anonymous said...

I too prefer midlengths:

Angus McThag said...

You may also want to re-think the Fulton 4-rail handguard. The symmetrical round ones are like gripping a coffee can.

LaRue and Daniel Defense make them that aren't round where the 3,6,9 o'clock rails are closer to the barrel. Much nicer to hand onto, especially after you put some sort of rail protector on.

Another one to consider is the style that has no rails on the 3,6,9 except for the very end, like a YHM Smoothie.

Geodkyt said...

True, what Angus says.

Anonymous said...

model 1 sales sells complete kits minus lower

Fiftycal said...

Stock triggers sux. Look at the Rock River trigger, $90 or so. Well worth it. Also, the telescoping stock sux. With proper optics (red dot, Trijicon ACOG, etc) you dont' need much eye relief. I like the short ACE solid stock. It's also cheaper. And Yankee Hill Machine makes a super upper for about the same as the Fulton. And you can get a cheaper upper from DSA. Since the 223 recoils very little, I like to keep my AR's lite. You probably won't need to bust off 200-300 rounds in a day and a lite carbine barrel takes a few oz. off the gun. Spend more on the optics than the gun.