Myth – “To shoot well you have to use the tip of your trigger finger.”
Fact – The only factor is can the shooter consistently press straight to the rear without disturbing alignment.
FM 3-22.9, Page 7-3, Figure 7-5
“The trigger finger (index finger on the firing hand) is placed on the
trigger between the first joint and the tip of the finger (not the extreme end) and adjusted depending on hand size, grip, and so on. . . . It is important to experiment with many finger positions during dry-fire training to ensure the hammer is falling with little disturbance to the aiming process.”
Both humans and firearms vary greatly in size and shape. To make a general rule that every person must index the controls exactly the same on every type of firearm is ridiculous. The only factor that matters anyway is that the trigger is moved straight to the rear without adding any addition motion. Start by taking a strong grip on the cleared firearm, letting the index finger lie across the face of the trigger wherever is natural, and pressing the trigger straight to the rear while watching and maintaining sight alignment.
If alignment can be maintained through the trigger press the shot will be true. The firearm doesn’t know or care what part of your finger you use.