If he is, and I don't believe he is, he's not showing it by explaining his action or by stating his opposition to more federal gun restrictions. I've never heard of him voicing an inclination to repeal the Lautenberg amendment, for example.
And assuming the feds have plenary power of RKBA and 2nd amendment issues, why doesn't he propose a federal law that forbids states to pass magazine size limitations? I mean if the feds can restrict, they can also limit restrictions.
Limiting restrictions is precisely what he is trying to do in his amendments to the Manchin Toomey Proposal.