From what I understand of the U.S. Constitution, interstate commerce is the ONLY Constitutionally-based inroad the feds have with respect regulating firearms AT ALL. Even then, much of their regulation has infringed on the right to keep and bear arms, and has thus violated the 2nd Amendment.
I think the foundations of these eight states are sound, and hope the 9th U.S. Circuit Court of appeals has done their Constitutional+Amendments homework, particularly the part about "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
There are ZERO powers delegated to the United States by the Constitution giving it any authority whatsoever to regulate firearms manufacture or sales within a state. I think the case was never more clearly stated than by James Madison, who endorsed the 10th Amendment, even though he believed it was unnecessary as the Constitution already contained verbiage along the same lines:
Good luck you, Mr. Marbut, Montana, Alaska, Arizona, Idaho, South Dakota, Tennessee and Wyoming!I find, from looking into the amendments proposed by the State conventions, that several are particularly anxious that it should be declared in the Constitution, that the powers not therein delegated should be reserved to the several States. Perhaps words which may define this more precisely than the whole of the instrument now does, may be considered as superfluous. I admit they may be deemed unnecessary: but there can be no harm in making such a declaration, if gentlemen will allow that the fact is as stated. I am sure I understand it so, and do therefore propose it. (The Founders Constitution)