Nine hundred ninety-nine reloaders/shooters/hunters out of 1,000 cannot tell the difference between a "true Kieth" bullet or any of the many copies/variations either in accuracy, effects on game, or shooting qualities. Maybe during a close inspection with measuring tools and blueprints of each bullet some could find differences. Perhaps Keith himself could tell the difference from his original design and a Lyman 429421, but I am sure no one reading this forum could...
Perhaps someone could preform a test, side by side between a "true Kieth" and say a 429421 or any of the clones. A few hundred rounds of each then a "blind test" where the shooter did not know hat is chambered. I don't have that much interest in this subject as my Lyman 429421, my "Thompson design" 44 cal w/gascheck and my RCBS LSWC are very accurate in my 4, .44 Magnum handguns...