You can ship ammo to NYS, I use to do it all the time before i handloaded. there is a haz mat surcharge for ammo, powder and primers, I think its 25$ or something even if its just a few boxes so it might not be worth it, unless youre buying alot at once. Somtimes when I buy ammo and primers on gunbroker,sellers dont charge the hazmat fee because they just put it in a flatrate USPS box and dont say what it is.
http://www.gunbroker.com/Auction/Vie...Item=209115210