I have a Fulton Armory M16A1 C7 upper with the A-1 type sight. What is the correct way to index the sight disc on the right side? All the sight installation informationI have seen only applies to the A-2 type. Is there a correct position for the number 1 on the disc during installation?

Index it any way you want. If there's a set position during installation, it goes out the window as soon as you zero it.

Oh, by the way, does the interior of your Fulton upper have any tooling marks like this?
Fulton M16 upper:

Yes, as a matter of fact it does. There are faint machining marks on the part of the receiver where the bolt carrier rides. Thanks for the info about the rear sight. Didn't think it mattered, but you never know.

I think that all those C7 type uppers, no matter who is selling them, ere all made by the same people at the same time. Even the Bushmaster version, which only differs in having the solid lube coating inside, has the same 1) tool marks, 2)really tiny Anchor Harvey forge mark, and 3) the windage arrow on the side doesn't have an "R" under it.

At least the DPMS piece I have, and the Bushie ones I've seen are all like that---and the tool marks on the pic of the Fulton unit makes me suspect that the above holds true for their units as well.  Oh BTW, is the channel for the cocking handle snug unough so that many units, especially Colt handles, won't fit?

Don't know about the charging handle channel. I haven't assembled the upper yet. It does have an H with a triangle above it. I assume that is the mark you are refering to. And it does not have an "R" under the arrow. But above the arrow is what looks to be a number 1. My barrel from Bushmaster is supposed to arrive on the 7th. So then I will be assembling the entire unit.

If you would like to upgrade the A1 sights, let me suggest:

Square A2 front post

Replace the rear sight blade with A2 large aperture type.

Toss the windage drum and use a Rapidex Windage Knob, which has 1/2 moa clicks.  (Available from DPMS and Bushmaster, as well as other sources)

This will give you sights that for all practical purposes are as good as A2's.

Quoted: Don't know about the charging handle channel. I haven't assembled the upper yet. It does have an H with a triangle above it. I assume that is the mark you are refering to. And it does not have an "R" under the arrow. But above the arrow is what looks to be a number 1. My barrel from Bushmaster is supposed to arrive on the 7th. So then I will be assembling the entire unit.

Yup, same batch. The number 1 isn't a one.  It's the reference mark for whatever number you keep the windage wheel on.  When you do try a charging handle, don't be surprised if it's real tight---especially if it's a Colt piece.  All but one of mine are Colt, and the afdtermarket piece was the only one that fit well.  The "triangle" above the H is actually an Anchor/Harvey "A", but it's so small that it does appear to be a triangle.

Still, if you're building up a C7 clone, which I was, that upper, no matter who you get it from, is the only game in town

Thanks for the info guys. When I ordered the upper I also ordered an upper parts set. but I had them switch out the A-1 rear aperture for the A-2. I will be using an A-2 front post. I prefer the A-1 type of sight. I like to keep things simple. The AR is my short ot medium range rifle. I have my other AR zeroed at 50yds which should keep me in the kill zone out to 250 meters or so. For anything longer I have a .308 heavy barrel which shoots better than I can hold it. It wants to put every bullet in the same hole. Unfortunately sometimes the rifle and I have a difference of agreement.

Someone mentioned the Rapidex Windage Knob for replacement on a A1 upper.  Is this a fairly simple job?  If one were to purchase the knob from Bushmaster ($10.00), is everything included (small parts) or is it simply a "knob" and you re-use the older parts?  Also, to replace the front A1 sight (round post) with the later A2 version (square post), do you really need a A1 front sight tool?  Thanks.

you would need an A2 tool (4prong) for the new front site, the A1is a 5 prong
the rapidex i installed years ago came with a ball. spring, and longer roll pin
and i works great
rlc

Quoted: you would need an A2 tool (4prong) for the new front site, the A1is a 5 prong the rapidex i installed years ago came with a ball. spring, and longer roll pin and i works great rlc

Don't have the Bushie catalog right here, but seem to remember they Rapidex blurb instucts purchasers to reuse the original pin. Ball and spring aren't mentioned.