> I'd like to see someone explain why a .50 BMG bolt action upper receiver (AR-15 type) is a firearm but a .556 bolt action upper receiver (AR-15 type) is not

Have you petitioned to have the rule revisited? I’d imagine this is the right political climate in which to do it.

We have an overreaching regulatory state. I agree with you on that. But trying to ram everything through the Congress just means we get a President who is a king, because the complexity of administering a large, modern economy is simply not one that can be centrally deliberated in the way legislative bodies work.