An open-ended grinding mill (1) includes a drum (2) including a cylindrical shell (3), wherein the longitudinal axis (4) of the drum is arranged in a substantially horizontal position in a use position of the grinding mill (1). The drum (2) includes a first end (5) at the feed end of the shell and a second end (6) at the discharge end of the shell. The grinding mill further includes a bearing (8) supporting the drum at the second end, and a support structure (9) to connect the drum (2) to the bearing (8). The support structure is configured to provide a wall external to the shell, whereby the shell and the support structure provide a double-wall structure separating the bearing from the inside of the drum.