Take some white shoe polish and put a small dab on the edge of the rim and tire, if it moves install the screws scope wrench
I think I used #10x3/4 inch long course threaded sheet metal type screws with a 6 sided hex head to make it easier to install and remove up scope
I had used regular head screws in the past, Phillips and standard straight cut in the past until I switched wrench
I inflate the tires up above 25 Lb. and use a small drill bit a little smaller than the body of the screw to drill the rims and a short way,(3/5 to max of 5/8 inch) into the tire bead to allow the screws a good start into the beads wrench
IHTHs

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)