I suggest modifying/blocking at least one magazine down to a 5 round capacity yourself or through an FFL, and submit a "receipt" of the magazine work done with your registration. From what I've heard the tyrants at licensing division are semi autistic and may deny your rifle registration because it can hold more than 5 rounds. If you want to truly play by the rules if you can you may keep some 10 round magazines outside city limits. I'm not sure what the penalty is for having 10 round rifle magazines in deBlassio's communist kingdom but you want to avoid anything that may jeopardize your rifle permit. Good luck, let us know if you are successful in registering the Browining T-Bolt.
Thanks for that -- good idea about keeping an extra-NYC version of the magazine.