Has anyone in history ever done a comprehensive testing, or evaluation, of single triggers such as the Hunter One Trigger, the Miller, the Kautsky, the Infallible, etc.?
Those of us who have messed much with them may have preferences and/or opinions, but we all likely have a very small set of experiences to go on. I've had perfect results from HOTs, two of which I own at this time, but little to no experience with the others.
I would note that in more modern times the single selective trigger for shotguns has been , for all intents and purposes, perfected. You can put tens of thousands of rounds through Berettas, Brownings, Zolis, Guerinis, Perazzis, Kreighoffs, Kolars, etc. without a single issue. But, what about the vintage jobs? Has anyone ever carefully and fairly evaluated them?