This half scale 3” Ordnance Rifle has a custom cast and turned bronze barrel with a rifled 37 millimeter sleeve for the bore. The cascable knob (at the back end of the barrel) unscrews giving access to the breech for cleaning; the gun loads from the muzzle, however. I understand it is extremely accurate in competition, consistently keeping ten shots within an eighteen or twenty inch circle at a range of six hundred yards!