It also sounds like the tools are not necessarily the proper size........I use Judd setters and have 3 sizes..........I have never had the problems you described unless I tried to set on a too soft surface as Dwight said. also not setting the washer tight or the piece moving while you set will cause these problems.......A combination of the right tools, proper surface, and hitting directly down and not a glancing blow will result in a better looking rivet. PRACTICE................as again Dwight suggested