The old post had problems with links and had aged a bit, so here's the update on my completed project:
A few years ago, right before the ATF blocked imports of anything interesting, or should I say, "not for sporting use," I acquired a couple of original AR-10 kits; one Sudanese and one Portuguese. I built up the Sudanese gun awhile back, but I finally managed to get a CNC'd lower made for the Portuguese gun. Here's the kit, and the CNC receiver is on the upper left.
Here are a couple of pictures of the shiny new receiver, before fitting:
As it turned out, this receiver needed more than a little bit of elbow grease to finish up, getting holes lined up properly, getting the mag well squared away and a few other things.
First, I had to assemble the machined lower and parts to check for fit and function.
Even though the receiver was CNC made, I still had to do a pretty fair amount of fitting and filing to get things to move smoothly.
As you might expect, the original AR-10s go together very much the same way as the AR-15. The Sudanese model is a lot more like the AR-15 we know, but the design of the Portuguese, or "NATO" variant was modified by Artillerie Inrichtingen and seems to have been influenced a little by the FAL. There are a few significant differences from what we're used to with the AR-15, such as a more complicated bolt catch, mag catch, etc.
The handguards are a bit more complicated than on the AR-15. There is an internal metal heat shield that has top and bottom halves and then there are left and right fiberglass handguards that go over the heat shield. The heat shield and handguard parts are not identical, but are different parts as on the early AR-15 - note the slot on one of the heat shield halves for the gas tube.
The Portuguese AR-10 had a lug (where the AR-15's charging handle would be located) to keep the charging handle from running out and jabbing the shooter's hand. I had to attach a rectangular piece of aluminum to the receiver and then give it the proper profile with a disc sander. You can see the difference in the next photo, and those above.
Next is a picture of the receiver after sandblasting, and before final finishing.
I used Norrell's semi-gloss black moly-coat to finish the receiver. It's not a perfect match, but pretty close. The original receiver wasn't a perfect match, either.
And here's the assembled rifle, with its older brother in the background.
Nice photo showing the Portuguese AR-10 in the foreground, and the Sudanese version behind it.
Another shot of the two, side-by-side.