I was bottom tapping some 10-32 holes and having a little trouble figuring out when I was bottomed. I am right handed and when I switched to my left hand for a little break I found my non-dominant hand was markedly more sensitive as to when I needed to back out to break the chip and when I was bottomed. Im sure many old hands do this instinctively, but for me it was a eureka moment. Since I have never seen it mentioned before I thought I would put it out there.
Bill
Bill