Get Bent

With all "Parts Kit" guns, the receiver is destroyed or missing entirely.  As shown in my first AK post, with AK variants it's the latter.  To lower the cost and speed up production, the Soviets switched from a milled steel to a stamped sheet metal receiver when they switched from the original design of the AK47s to the AKMs in the mid 50's.  This makes AKM receivers fairly easy to make with some skills and the proper tools.  There is a thing in the AK world known as a Receiver Flat.  It's basically a flat piece of sheet metal with some holes stamped in it.  The BATF has determined that a flat is not a firearm and because of this, they can be sold to anyone without having to go through a licensed firearms dealer.  Here's what the AK receiver looks like(not my pic):

To build an AK receiver, we'll need some special tools.  The very first step is to get the thing bent.  A regular brake won't work because the bends are deep and at 90°.  To make sure everything stays straight and square, a special bending jig is required.  Like everything else, jigs are available online, but are far too expensive for a one time use.  So, I made my own using some 1/4" angle iron, some 3/8" plate, and a hunk of aluminum.  After making a jig to make the jig, here's what I ended up with:

There's not much to it, but the spacing needs to be fairly exact.  The receiver flat gets bolted between the "T" steel and the aluminum block.  I don't have any pictures of the actual thing, so just pretend that this cardboard is our flat:

Then you put the jig in a press, and press the thing down.  The aluminum block acts as a guide to make sure it gets pressed straight.

When it's removed from the jig, you're left with a bent AK receiver(again, not my pic):

Congratulations, you've just turned a piece of sheet metal into a firerarm.  The instant it's bent, even though it's no where near being complete and shootable, it's now a firearm in the eyes of the BATF.  With the flat bent, the rest of the parts can be mocked up and test fit: