Here's an interesting freebie borrowed from Facebook

[jond41403]

Are those round metal billet looking things stacked at the bottom of the picture what the receivers start out as? Yes you can definitely tell this is a cutting machine. Notice the little hook like thing to the left of the cutter that would grab the end of the receiver and swivel down locking it onto that little square platform for the cutter to then come down and cut off the excess. You can tell it's made to be loaded exactly how he has it oriented in the picture. He is fixing to lay it in that cutter bottom side up. I believe the structure on the left is a brace. The hook to the left of the cutter that holds the end of the receiver would prevent it from sliding down that brace. I believe he would have to unhook the receiver and then lay it on that brace to slide down but it would make more sense that if he had to unhook the receiver he would probably just turn and throw it in a bucket somewhere out of view in the picture

[browningautorifle]

Are those round metal billet looking things stacked at the bottom of the picture what the receivers start out as?

I believe they are the raw stock. Grab one and get at it.

You can see the receiver legs sticking up on the red hot forging.