Nice looking tool...Reminds me of the one I fashioned from the clamp part of a tube flaring tool years ago, dy drilling out just a smidge oversize of the two calibers I used back then...Fast and simple...Trouble was tightening the wing uts any too much would easily "squash" a thin jacketed bullet out of round..You couldn't see that with your naked eye but the Starret would pick up a tenth or two....If it was too loose and broke grip on the bullet it would score the copper...My collet puller doesn't deform like that but most times leaves a mark/ring...
What material is the Grip-N-Pull?....Will it squeeze "soft" enough not to deform them but enough to hold them without slipping?...There are probably some "space age" materials out there that might fit that ...
Thanks for sharing,
Randy