Their policy, effective 4/30/03, is that they will not sell any ammunition to NYS residents, but it is not based on any new law that was slipped by without notice.
It is apparently a case of their legal council reacting to New York State Penal Law Section 270.00(5):
Others have reported that in conversations with a phone representative at Kieslers, they were told that they were advised that any liability incurred by "potential violations" was not worth the risk, and that they had adopted a blanket policy towards ammo sales to NYS.5. Notwithstanding the provisions of subdivision four of this section, it shall be unlawful for any dealer in firearms to sell any ammunition designed exclusively for use in a pistol or revolver to any person, not authorized to possess a pistol or revolver. The violation of this section shall constitute a class B misdemeanor.
In other words, Kiesler could legally sell NYS residents ammo, but they simply choose not to!
I salute them!
If I was in the business of selling ammunition and/or firearms parts,
I would simply refuse to do business with anyone in certain states
such as California, Massachusetts, and New York..it just isn't worth
the hassle trying to keep up with all the damn laws that get passed
in those parts, and I'd like to stay out of jail...