From Bob Hanna of my historical handgun research team, a 1978-79 era document from Gunsite & Jeff Cooper listing his three rules for gun safety. Three? Conventional wisdom within the firearms training community is that Cooper’s “Four Rules” Shall Not Be Questioned, as I did in an older post about reducing his Four Rules and the NRA’s Three Rules down to two.

This early version of Cooper’s rules doesn’t address attention to the trigger finger at all, which seems like a glaring error to me. (My reduced safety rules are to pay attention to muzzle direction and trigger finger placement, in that order.) Granted, if someone pays attention to Cooper’s three rules, the worst that can happen is a negligent discharge in an acceptably safe direction. Inattention to trigger finger can absolutely result in a “mishap” with a gun. Attention to trigger finger does appear in the document, down at #6 in the Gunsite Ground Rules.

According to Bob, the addition of the trigger finger rule to the official safety rules occurred sometime in the early 1980’s.