I thought it would be useful to have a way of presenting the bucking bar to the shop end without having to keep such a close eye on it being square to the rivet. To that end I designed a prototype holder for my bucking bar. I can then concentrate on the factory side with the rivet gun. The holder could be clamped onto the surface without the rubber bands. The bar can then be inserted into the holder. It is also possible to just free hand the foot to be square with the sheet metal. The rubber bands will hold the tungsten against shop head during riveting.