You may want to check how far the front element of the TC14 sticks out and how much space is there between the back element of the 150-500 and mount base. If there is not enough clearance, the front element of the TC will ram into the back element of the 150-500. May be better to use the sigma tc especially if they have one that is designed to be used with 150-500 like the 14e is designed to be used with certain nikon lens.