It looks like Justin Amash and Thomas Massie both voted NO on this one.
State’s rights concerns maybe?
Nope. The Constitution is very clear about that. The 10th amendment:
"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."
The Constitution seems to have made clear this issue of reciprocity in the 2nd amendment: "...the right of the People to keep and bear arms shall not be infringed." Thus, it is not a States rights issue.
Let the States bring their lawsuits. They'll lose in the USSC.