Just checked about 3 steel cases all were .314 ID and as I recall bullets are .310 - .312...my .308 dia bullets just dropped inside the case...so it seems that resizing may be in order but that was part of the heat 'em up first idea was to increase ductility to enable resizing w/o brittle results. One of my concerns would be whether or not 250 degrees would be hot enough to get the desired/required ductility.