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russ 11-16-2011 06:37 AM

My upper build thread
This thread will try to show just how easy it can be to build your own upper. Just like doing your own lower, the key is to do your homework before you start ordering parts. Selecting the right parts to compliment each other is even more important on the upper, as many combinations of parts just won't work together.

For me, the only real concern I had before starting this build was with the gas block. Getting it aligned and secured properly had me a little worried. I was just minutes from pulling the trigger on ordering a stripped Daniel Defense barrel and a low profile gas block from Midway, when I saw this barrel on AIM Surplus:
It was cheaper that the same barrel from Midway (with the arfcom discount code at AIM) and it had the FSB already pinned, but not locked down. Saved me about $20 on the barrel and $25 by not needing a gas block, plus it solved my dilemma. So I ordered the barrel assy. and complete DD BCG from AIM.
I also ended up ordering the gas tube from AIM, after I goofed and ordered a rifle length tube from Midway. :rolleyes:

The DD upper receiver, Troy rail, BCM charging handle, Magpul sights, and Magpul AFG2 all came from Midway.

russ 11-16-2011 06:59 AM

Here's where some homework pays off - the Troy TRX Battle Rail comes with a barrel nut and the correct wrench to install it. Two more things you don't have to mess with. Troy instructions are pretty good, and they give you torque specs for the barrel nut, but you could always just Google stuff like that if you needed to. I opted not to buy a receiver vice block, instead I just clamped the upper in the vice like so:
Now this little vice was just for photos, I used the big vice in my garage to torque the barrel nut down, but it's cold out there now, so this is it. The barrel nut design can vary a great deal depending on the fore end you decide to use, so you may have a different setup than this. The Troy barrel nut has to be aligned with the opening in the upper to allow the gas tube to pass through without interference. They give you a range of 30-60 ft-lbs to make this happen. As luck would have it, 30 put the nut with one of the "teeth" perfectly in the center of the gas tube hole. So I reset the torque wrench to 60 and started turning. 60 was just shy of being perfect, so I backed the nut off and then ran it down again in an attempt to "relax" the fit a little, and get it to align without having to over-torque it.
It is very important to note that if you are using a barrel nut wrench like this, you need to have it at 90 degrees to your torque wrench like I do here. If you have it straight out to the front, you will be over-torquing your barrel nut. The extra length will throw your torque setting off, so by having it 90 degrees to one side or the other, you eliminate that problem.

russ 11-16-2011 07:02 AM

I'll finish up tomorrow, it's late and I'm beat.:p

Quentin 11-16-2011 02:01 PM

Hey, great thread and great pictures Russ! Thanks, this could develop into a sticky!

Glad it's coming along well and like you say, the upper is much the same as building a lower, do your homework and buy quality components. Thanks for sharing...

mjkeat 11-17-2011 12:29 AM

Good stuff Russ.

You purchased the DD upper from Midway?

russ 11-17-2011 04:25 AM

Sure did. I'll put prices and sources at the end.

Back to the build!
The gas block: I cheated here. Using the FSB that was already properly aligned by DD took all my worries out of the picture. Then I cheated again. After chopping the big chunks off with my die grinder and a 3 in. cutoff wheel, I took it to work with me and did some more whittling on the Bridgeport. After a little touch-up with the grinder and a coat of high temp paint, this is what I ended up with:
Next it's time to attach your gas tube to the gas block. Again, check what you're ordering, some of the tubes I looked at came with the roll pin and some didn't. The Spike's tube came with two! Do yourself a favor and put a slight chamfer on one side of the pin hole in the gas block to help start the pin, it can be a PITA. The alignment should be obvious, there is one blind hole that lines up with the through hole to the barrel, and one through hole for the pin to secure the tube to the gas block.
Once that is done, you can mount the block assembly to the barrel. If your pinning your own block or using a set screw or clamp style, you can use the gas tube to help you align it. If everything is correct, your tube won't touch the sides of the receiver hole at all. It should sit perfectly in the center of the opening.

russ 11-17-2011 04:37 AM

The you can secure the block to the barrel. Tapered pins for me. Block the barrel up so it sits level and is supported, then a few good smacks with a hammer and punch.
Then I went back to the vice to attach the comp. I'm going to wait until the break-in and any troubleshooting is over before I permanently attach it.
Almost home! Now attach the fore end of your choice. Troy VTAC TRX Battle Rail is what I chose. It simply slips over the teeth on the barrel nut and then rotates slightly for alignment and clamps down with two allen head bolts. Easy peasy.
Then you slip in your charging handle and BCG as if you'd just finished cleaning your baby, and it's done. Attach to your favorite lower and adorn with accessories of your choice. I'm a Magpul whore, so this is my finished creation:

russ 11-17-2011 05:06 AM

And with the EOTech mounted:

Hope the weather holds and I can burn some powder this weekend.

Sources and prices:
AIM Surplus
DD Barrel assy. - $239 (w/ arfcom discount code)
DD BCG - $129.95
Spike's gas tube - $14.95
Free shipping from AIM.

DD upper receiver - $120
Troy TRX rail - $189.99
BCM Mod 3 CH - $44.95
Shipping $10.14

For a grand total of $748.98

All in all, a pretty decent price to get exactly what I want. Plus I really enjoyed building this.

If you have your stuff together and don't have to screw around with anything like turning an FSB into a low profile gas block, you could knock this out in under two hours.

Feel free to ask questions, I'll try to answer them if I can.

Axxe55 11-17-2011 08:33 AM

:Dvery imformative russ. picked up some valuable info on building uppers. thanks, for taking the time to illustrate how it's done.

mjkeat 11-17-2011 10:27 PM

Great write-up russ.

That's a super nice rifle. Great parts, good looking AR.

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