Can we get specifics on materials? Whats the bolt, carrier, and trunnions made from? Whats the barrel material and treatment?

Is the barrel american made?

It is in the original post.

Review here http://www.gunsandammo.com/tv/high-standard-ak-47-barrel-receiver-kit

Looks like a cool option for "sort of want to build my own AK" folks like me.  No presses or special tools needed.

But why does High Standard not ever put side rails on their AKs?  That's the only reason I didn't buy a whole AK from Atlantic back during the rush - no side rail for optics.

Edit:  Why include extra rivets?  That just makes people think they need a press, and they don't.  But they will look at the pics and move on when they see rivets, I bet.

Trigger and hammer are not installed, so that is why the rivets are needed.

Looks like the others are for the trigger guard, but not sure. Might just be how the rivet kits are packaged.

The trigger and hammer don't require any rivets. Those long rivets shown are for the rear trunnion. Looks like a complete AKM rivet set.

Gotcha. I brain derped on the trigger pins.  

Do the same thing with a short barrel, sell the entire thing as a pistol receiver and I will buy a few.

I like Brownells and have purchased from them many times. However, although I do not wish to rain on anyone's parade, based on my own personal experience with an Interarms AK47 I purchased from an online firearms dealer last year, pre election, I would not want any firearm made by Interarms or High Standard. The Interarms AK I purchased functioned OK, but it was way below what I expected for $679, + shipping and FFL fees, at the time (pre election).

I purchased the Interarms (owned by High Standard) AK47 with the traditional red wood furniture and was very disappointed. I ordered it from an online-store, and had it shipped to my local FFL dealer. It looked good in the pictures, and I too searched for info on the Interarms AK, and could not find much. A couple of positive reviews but nothing too bad.

At a quick glance, it looked good when I picked it up at the FFL dealer and did the paperwork. When I got it home, and upon further inspection, there was one really sloppy/crooked rivet on the top left side of the rear trunion (rivet crushed crooked). The triggerpin hole on the right side was too large for the pin, and you could see the pin move back and forth in the pin hole in the receiver when you squeezed or moved the trigger. You could look inside the receiver a see that the bullet guide was installed a bit crooked.

The gun functioned okay, though I only fired about 30 rounds or so through it. I also noticed that there was a bit of mushrooming/peening on the rear of the bolt carrier
(cast and not forged/milled), where it contacts the hammer when cycling (after only 30 rounds). Like I said, I was disappointed, although most of the fit and finish was decent. I called the dealer I bought it from and complained about the sloppy rear trunion rivet. He contacted customer service at High-Standard/Interarms, and the guy (with cs @ HS/I) wanted pictures of the rivet. I sent the pictures, and he said if I paid to ship it back to them they could take a rubber hammer and fix the rivet. That was all I needed to hear... really? A rubber hammer to fix a bad steel trunion rivet? Also, you could see a space/gap at the top of the rivet hole in the receiver, (where the bad/crooked rivet was installed) which likely caused the rivet to compress crooked (receiver rivet hole/trunion misalignment).

Also, and I'm not sure if this normal or not, but the traditional slant-break flash hider was very loose on the threads. You could wiggle it easily while locked in place by the retainer. There was a big gap between the upper and lower hand-guard, and if you looked at it from the top end, the top and bottom hand-guards were not in-line with each other, but one was off to the side a bit, and it was very noticeable, both visually and by touch.

After a few months, I was so dissatisfied with it I traded it in at a gun store and took my loses.

Here are pics of the sloppy rivets.