I've not seen a single online dealer (even before the SAFE Act) that would ship to NYC. I read a good while ago that you're not allowed to have any ammo that doesn't fit the guns on your registration. I found a document that lists NYC laws and mentions:
"NYC Title 38 - Subsection 1-05 (k) No ammunition suitable for use in a rifle of any calibre, or for a
shotgun of any gauge, shall be sold, given away, or otherwise disposed
of to any person who has not been issued a rifle/shotgun permit and a
certificate of registration, and who does not exhibit the same to the
dealer at the time of purchase. Rifle or shotgun ammunition shall not be
sold to any such person except for the shotgun or for the specific
calibre of rifle for which the certificate of registration has been
issued.No ammunition suitable for use in a rifle of any calibre, or for a
shotgun of any gauge, shall be sold, given away, or otherwise disposed
of to any person who has not been issued a rifle/shotgun permit and a
certificate of registration, and who does not exhibit the same to the
dealer at the time of purchase. Rifle or shotgun ammunition shall not be
sold to any such person except for the shotgun or for the specific
calibre of rifle for which the certificate of registration has been
issued."
Everything in NYC is extremely tightly controlled. Possession of said ammo that doesn't fit something he has registered is a crime. I think this is why nobody ships there. NY State outside of NYC doesn't have such restrictions.
http://newyorkcityguns.com/nyc-title-38-nyc-specific-firearms-laws/