Homemade Barrel Crowning Tool

This is a good, lathe-free expedient in the sense of metal removal. Yet cutting tools burr metal down into a recess, such as what exists next to the lands. Hence, a crown is incomplete until lapped. Typically this is a large brass roundhead screw chucked in hand brace or low rpm drill. The slot carries lapping compound. So, plug the bore with patch and ball if breech is still open. Use easier removed material otherwise. The ball of the roundhead will cut evenly on its own accord and 100% tangent to circumference. While the screw rotates, create a figure-8 motion. Use layout fluid or felt tip pen to monitor progress When a frosted area is visible over at least part of the lands and just smaller than groove diameter, that signifies completion. Flush and clean scrupulously with clean liquid that lapping paste is based on. Your patches will love you, same as lead or copper jackets.