Thompson Center Hawken Barrel. 15/16 across the flats. Off set scope mount so iron sights can still be used. Rear hole for scope mount was drilled completely through breech plug, since this is solid steel, this doesn’t effect bore. Ships to USA address only. The item “Thompson Center Hawken Barrel 45 Caliber” is in sale since Thursday, March 21, 2019. This item is in the category “Sporting Goods\Hunting\Vintage Hunting\Black Powder”. The seller is “saxtonyoung” and is located in Smiths Creek, Michigan. This item can be shipped to United States.