A gyratory crusher outer crushing shell comprising: a main body mountable within a region of a topshell frame of a gyratory crusher, the main body extending around a central longitudinal axis; the main body having a mount surface being outward facing relative to the axis for positioning opposed to at least a part of the topshell frame and a crushing surface being inward facing relative to the axis to contact material to be crushed, at least one wall defined by and extending radially between the mount surface and the crushing surface, the wall having a first upper axial end and a second lower axial end; a raised first contact region positioned axially towards the first upper axial end and extending radially outward relative to the mount surface and in a direction around the axis, the contact region having a radially outward facing raised first contact surface for positioning opposed to a radially inward facing surface of the topshell frame; a raised second contact region positioned axially towards the second lower axial end and extending radially outward relative to the mount surface in a direction around the axis, the second contact region having a radially outward facing raised second contact surface for positioning opposed to a radially inward facing surface of the topshell frame, the second contact surface extending continuously over the mount surface and around the axis; and a channel extending around the axis and recessed radially inward relative to the first and second contact regions to axially separate the first and second contact regions. characterised in that: the first contact surface is discontinuous in a direction around the axis via at least one groove extending radially inward within the contact region to provide a pathway through the raised first contact region in the axial direction between a region of mount surface at the first upper axial end and the channel. a main body mountable within a region of a topshell frame of a gyratory crusher, the main body extending around a central longitudinal axis; the main body having a mount surface being outward facing relative to the axis for positioning opposed to at least a part of the topshell frame and a crushing surface being inward facing relative to the axis to contact material to be crushed, at least one wall defined by and extending radially between the mount surface and the crushing surface, the wall having a first upper axial end and a second lower axial end; a raised first contact region positioned axially towards the first upper axial end and extending radially outward relative to the mount surface and in a direction around the axis, the contact region having a radially outward facing raised first contact surface for positioning opposed to a radially inward facing surface of the topshell frame; a raised second contact region positioned axially towards the second lower axial end and extending radially outward relative to the mount surface in a direction around the axis, the second contact region having a radially outward facing raised second contact surface for positioning opposed to a radially inward facing surface of the topshell frame, the second contact surface extending continuously over the mount surface and around the axis; and a channel extending around the axis and recessed radially inward relative to the first and second contact regions to axially separate the first and second contact regions. characterised in that: the first contact surface is discontinuous in a direction around the axis via at least one groove extending radially inward within the contact region to provide a pathway through the raised first contact region in the axial direction between a region of mount surface at the first upper axial end and the channel. the first contact surface is discontinuous in a direction around the axis via at least one groove extending radially inward within the contact region to provide a pathway through the raised first contact region in the axial direction between a region of mount surface at the first upper axial end and the channel.