The POLAR and Teddy have the exact same barrel tennon dimensions! The Panda has a much shorter tennon length! If you have the old barrel, that will help a gunsmith get dimensions, plus take his own dim. from the action to chamber you a barrel. Take it to a very competent benchrest gunsmith. Kelbys may chamber you one also. They know all about them. Great actions!! Samuel HallA shortened polar becomes a teddy or a panda. No problem to work on it- you either use remington parts or kelbly parts according to what bolt is in it