There is a fundamental change being proposed, and that concerns what is the "receiver" of a firearm.
Obviously, and since the beginning, of the term's use, the receiver is the primary part that the other needed parts attach to. It "receives" the other parts to make a firearm, hence it is the reciever.
The issue here, is that traditionally, there has only been ONE part designated the receiver and all the other parts were just parts that attached, and they want to change that. In part, it is because of our use of the terms, upper and lower "recievers". Had we (the industry) from the beginning, called the upper a group or housing, or anything but a receiver, I doubt their current proposal would have reached the point of serious proposal.
Look at what they want, they want any/all housings that contain fire control parts or part or all of the locking or firing mechanism to be considered ANOTHER receiver as well.
Under the current language of their proposed rule change, barrel assemblies such as on the Contender and others would not be considered receivers, but the grigger housing of an M1 or M14 or a Ruger 10/22 could well be, because they contain (receive) the fire control parts
So, if they get their way, welcome to having to go to an FFL and pass a bacground check to buy certain parts were not legally firearms but apparently will be if this is approved.
Welcome to the world of possibly becoming a Federal Felon because you posessed a piece of plastic or steel without the required number on it. Just as one is still at risk on state levels for having a spring loaded metal or plastic box in excess of approved limite...
I realize I'm in a distinct minority with the opinion that we should not have ever wasted our time and resources with laws concerning mere possession of inanimate objects.
Laws against or defining what may or may not be done with objects (including the harming of others) are an entirely different matter, or should be, in my opinion.
How can it be "right" to say ok, you can own a set of golf clubs, but not a 7 iron, because at sometime, somebody, somewhere, beat somebody to death with a 7 iron...???
The whole concept of blaming objects for the actions of people and using that as the justification for legally prohibiting or restricting ownership is, to me something that should have been left in the Middle Ages when "things" were "evil" due to demonic possession and therefore had to be surrendered to the Crown, or the Church (or their local agents). It's a SCAM, one that has been officially sanctioned and promoted by the people in power for centuries despite logic and reason showing otherwise.
This proposed rule change is nothing but another case of adding restrictions and requirements on those people already obeying the law and doing nothing to affect those who are not.
Just my personal opinion, and i believe worth every penny you paid for it..