No, it is NOT legal for you to transfer firearms to an out of state resident, as a C&R holder. Only licensed dealers can do so, only rifles/shotguns, and only in their own state, the out of state resident has to go to them, they cannot go there and transfer rifles. You would have to take your guns to an FFL there and let that FFL transfer them to your parents.
It's 18 USC 922 (b). The (b)(3) exception only applies to licensed DEALERS, I believe, because of the term "place of business" used in the statute. A licensed COLLECTOR will not have a "place of business".
http://www4.law.cornell.edu/uscode/18/usc_sec_18_00000922----000-.html
(b) It shall be unlawful for any licensed importer, licensed manufacturer, licensed dealer, or licensed collector to sell or deliver—
(1) any firearm or ammunition to any individual who the licensee knows or has reasonable cause to believe is less than eighteen years of age, and, if the firearm, or ammunition is other than a shotgun or rifle, or ammunition for a shotgun or rifle, to any individual who the licensee knows or has reasonable cause to believe is less than twenty-one years of age;
(2) any firearm to any person in any State where the purchase or possession by such person of such firearm would be in violation of any State law or any published ordinance applicable at the place of sale, delivery or other disposition, unless the licensee knows or has reasonable cause to believe that the purchase or possession would not be in violation of such State law or such published ordinance;
(3) any firearm to any person who the licensee knows or has reasonable cause to believe does not reside in (or if the person is a corporation or other business entity, does not maintain a place of business in) the State in which the licensee’s place of business is located, except that this paragraph (A) shall not apply to the sale or delivery of any rifle or shotgun to a resident of a State other than a State in which the licensee’s place of business is located if the transferee meets in person with the transferor to accomplish the transfer, and the sale, delivery, and receipt fully comply with the legal conditions of sale in both such States (and any licensed manufacturer, importer or dealer shall be presumed, for purposes of this subparagraph, in the absence of evidence to the contrary, to have had actual knowledge of the State laws and published ordinances of both States), and (B) shall not apply to the loan or rental of a firearm to any person for temporary use for lawful sporting purposes;
