Made a 6mm thick steel spinner complete with M10 coach screws, 2x M10 washers and 3 x 10mm M10 spacers. Screw in to a tree or post and blast away with the rimmy or .17 HMR. These spinners are fine with rimfire ammo (including High Velocity rounds) at 50m and .17HMR at 100m. Reducing the range to less that his will result in marks on the steel.