ironglow - I believe you have to be licensed to sell ammo. I believe ammo must be stored in some specific manner so as to preclude theft, and also possibly explosion from fire and the like.
You need to speak to someone who is already in the business in NY or speak with, possibly, DEC.
If you are somewhat whizzed, as I get with some dealers, about the lack of variety of ammo availalbe I would first recommend checking out some of the Graybeard sponsors, like MidSouth for example, to see what they offer and have it shipped to you (legal if u is old enuf). Check out our other sponsors too, there may be some valuable deals avialable for you. HTH. Mikey.