AT-ONE THUMBHOLE, MOSSBERG 100 ATR, LONG ACTION, FACTORY BARREL CHANNEL Barrel Dimensions: Point A = 1 3/8" and Point B = 7/8" Center to Center of Action Screws: 5 1/8" Over All Length of Part: 31 1/2" Comes with Boyds' 1/2" Rubber Recoil Pad. It is your responsibility to confirm the dimensions of your firearm with the supplied dimensions of our part. ATTENTION CUSTOMERS: If you are converting from a plastic stock, you will need to purchase a trigger guard from our Accessories page: ITEM # A09157, and an action screw from Mossberg directly, ITEM # 101532. All finished parts have been CNC inlet to Boyds' House Action. Variations may exist from firearm to firearm, minor fitting may be required to get that perfect fit to your firearm. Natural cosmetic imperfections such as minor knots, burls, heartwood, mineral lines or minor cosmetic fill work are not considered a defect and will be subject to the 12% restocking fee .