N.Y. Penal Law § 400.20

§ 400.20 Waiting period in connection with the sale or transfer of a\n rifle or shotgun.\n When a national instant criminal background check is required pursuant\nto state or federal law to be conducted through the National Instant\nCriminal Background Check System (NICS) or its successor in connection\nwith the sale or transfer of a rifle or shotgun to any person, before\ndelivering a rifle or shotgun to such person, either (a) NICS has issued\na "proceed" response to the seller or transferor, or (b) thirty calendar\ndays shall have elapsed since the date the seller or transferor\ncontacted NICS to initiate a national instant criminal background check\nand NICS has not notified the seller or transferor that the transfer of\nthe rifle or shotgun to such person should be denied.\n