You might want to read up on the second amendment and the doctrine of incorporation. The current SCOTUS precedent is Biltmore v. Barron, which held that there was no incorporation. Thus a state is free to make the possession of each and every gun held be a private citizen within its borders illegal.
SCOTUS may reverse that holding at some point (unlikely when it comes to incorporation), but until it does, the local gun laws in NYC are Constitutional.
I have come to learn that “Conservatives” have their own unique view of Constitutional Law.
Basically, everyone gets to decide on their own what is and isn’t Constitutional law, those nine people be damned.
Unless they vote our way.
Hell, I think we even have a rare meeting of the mind here between Liberal and Conservatives.