Abstract: An improved method of machines grooves forming Pearson notches in a pattern on hollow shell casings for munitions for at least one of increased functionality and/or performance. Rather than running a broach through a hollow casing, a CNC lathe with a multi-axis tool with cutting implement can precisely locate and form grooves along either an interior or an exterior surface of a hollow shell casing.

Abstract: An improved curling apparatus for curling the outer peripheries of container shells includes a plurality of inner rings vertically stacked and a plurality of outer ring-segments vertically stacked. Each of the inner rings have an outer surface and a groove in the outer surface which extends the entire periphery of the inner ring. Each of the outer ring-segments has an inner surface and a groove in the inner surface which extends the length of the outer ring-segment. The outer ring-segments partially encircle the inner rings with the inner ring grooves facing the outer ring-segment grooves. Each of outer ring-segments preferably has a unitary length extending about 240 degrees and an eccentric groove. The curling apparatus also includes a plurality of adjustment devices adapted to selectively move the outer ring segments relative to the inner rings to adjust a distance between the inner ring groove and the outer ring-segment groove at a desired location along the outer ring-segment groove.