I got some of those machined cases for .32 rimfire from Dixie Gun Works. They take an offset .22 rimfire blank as the primer. The blank slips in place snuggly but with no resistance, unlike when seating a primer in a centerfire case where some force is needed. DGW says to use a lead round ball and some black powder. I'll be shooting it in an antique Marlin revolver. I'm wondering if anyone here has tried them out. I am a bit concerned about leakage of gas around the perimeter of the .22 blank's base.