I want to build a complete upper from scratch but can't find detailed instructions including how to mount and headspace the barrel, rear sight assembly, forward assist assembly, etc.

There are excellent instructions for the lowerreceiver on this forum that I used to build my lower, but nothing I could find on how to build the upper. I saw the NRA article, but there wasn't enough information for a newbie to upper building like me. I am ordering  all the tools, but still need detailed, explicit instructions.

Any help is appreciated.


_DR

In the books section it lists a book that I used "Build Your Own AR-15", it has some pretty good instructions for assembling the upper.

[url]http://www.ar15.com/content/books/BuildYourOwn/[/url]

well i just took some pictures of my last upper build that i was planning on using in a how to build article, when i have the time.  If you have any specific questions i could email you a picture or two and maybe put some text to it, it might help me get off of my butt and put the article together.

Specifically, the details I was looking for for step by set instructions on how to mount and headspace the barrel, written assuming the reader knows very little about this procedure. Also step by step on assembling and installing the rear A2 sight. The lower receiver assembly instructions on this post were so clear and well written, that they convinced me I could do it.

But the most important thing I need to know is, how to mount the barrel, and all procedures through headspacing involved with barrel installation.


Thanks, all, for your suggestions.

I ditto DR question about barrel, I'm trying to decide whether to get the complete 16" 1/7 Upper or just the barrel from Bushmaster right now.  I'm thinking of doing it myself, but would like a NO BS assessment.

John

You can't "headspace" an AR barrel - you can only check to see if "headspace" is within spec by using  chamber gauges.  Headspace in a noun, not a verb.

For installation, here's [b]The Famous Homo Erectus Barrel Mounting Method[/b] -

You'll need a few special tools, like an [url=http://www.bushmaster.com/shopping/gunsmith/om-003.asp]Action Block[/url] and a [url=http://www.bushmaster.com/shopping/gunsmith/223-wrench.asp]Barrel Wrench[/url].  The [url=http://www.bushmaster.com/shopping/handguards/hgd-tool.asp]Handguard Removal Tool[/url] is nice to have, but not absolutely necessary.  I'm assuming you already have a vise, hammer and punches, files, and circlip pliers.

Forget the torque wrench and all those silly "tighten and loosen 17 times while waving a dead cat over the barrel nut and dancing naked in the moonlight chanting voodoo curses with your nutsack smeared with magic moly grease" procedures incessantly parroted my the Worshipers of Military Manuals who until recently confined their insanity to the Troubleshooting board but have now starting to infest and infect "Build it Yourself." In order to install an AR barrel, all you have to to is tighten a single nut until the notch lines up.

But first, stick your new barrel in your upper receiver and make sure there's no play in the barrel pin notch and the front sight base is straight up and down. If it's not, take a jeweler's file and open up the notch to bring the front sight base up straight. You can tighten the notch to remove all slop (very important!!) merely but taking a small hammer and punch, and with the barrel in place very lightly peen down the threaded area on the "loose side" of the notch. Be careful, use very light taps because it doesn't take much!!

Now that the front sight is straight, all you have to to is tighten one nut. I use a short (2-3 inch) stub of a gas tube in the bolt carrier key pushed into the upper receiver to keep the circlip, weld spring, and delta ring indexed. Spin the barrel nut on until it's hand tight, then lean on the barrel wrench until the next gas tube notch in the barrel nut lines up. If you're using the gas tube stub in the bolt carrier, you'll see it pop through the notch.

That's it!!! STOP!! You're done!! Install the gas tube and handguards and go shooting!!! The whole process should take less than 20 minutes. If it takes longer, you skin your knuckles, or you have to loosen and tighten the nut more than once, you're doing it wrong!!!

And that's how you mount a barrel.  In writing.   [:D]

Homo Erectus, thanks for the write up.  Sounds like one who does understand the purposes of torque values in military manuals (having served, I know their is a need to hold certain peoples hands and making sure they take you literaly instead of using their own judgement).  I'm wondering how many torque nazis out there are trying to figure out a way to apply a torque wrench to the screws on their buttstocks.

What about the front sight base, if this is being added or replaced, how does on ensure the front sight base is straight with respect to the index pin?