Abstract: A method of producing an annular nonuniform groove (106) in the bore wall (104) of a casing (100) and a casing produced thereby is disclosed. The method includes the steps of forming a first portion (164), forming a second portion (172), and forming a third portion of an annular nonuniform groove. The first portion is formed by a first milling tool (168). The first portion defines a starting point (108) as the radial furthest point on the radially outer surface of the first portion. The first portion also defines a first intermediate point (166) as the radially closest point on the radial outer surface of the first portion. The second portion (172) is formed by a second milling tool (174, 180). The second portion is defined along the annular radial outer side wall from the first intermediate point to a second intermediate point (178). The second intermediate point (178) is defined as the radial closest point on the annular radially outer side wall of the second portion.